Ti-2003 Science and Technology Proceedings of the 10th World Conference on Titanium

Volume I

Edited by G. Lütjering and J. Albrecht Ti-2003 Science and Technology

Proceedings of the 10th World Conference on Titanium Held at the CCH-Congress Center Hamburg, Germany 13- 18 July 2003

Volume I

Edited by G. Lütjering and J. Albrecht Editors: Prof. Dr. G. Lütjering, Prof. Dr. J. Albrecht Technical University Hamburg-Harburg Eissendorfer St. 42 21073 Hamburg Germany

10th World Conference on Titanium held 13-18 July 2003 in Hamburg, Germany Organizer: DGM • Deutsche Gesellschaft für Materialkunde e.V., D-60486 Frankfurt, Germany

This book was carefully produced. Nevertheless, editors, authors, and publisher do not warrant the information contained therein to be free of error. Readers are advised to keep in mind that statements, data, illustrations, procedural details or other items may inadvertently be inaccurate.

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© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

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Printing: Druckhaus Darmstadt GmbH, Darmstadt Bookbinding: Litges & Dopf Buchbinderei GmbH, Heppenheim Printed in the Federal Republic of Germany Organization of the 10th World Conference on Titanium

Conference Chairman:

G. Lütjering, Technische Universität Hamburg-Harburg, Germany

International Organizing Committee:

R. R. Boyer, ASM International (ASM), USA I. V. Gorynin, Association "Titan", CIS G. Lütjering, Deutsche Gesellschaft für Materialkunde (DGM), Germany M. Niinomi, The Japan Institute of Metals (JIM), Japan A. Vassel, Societe Francaise de Métallurgie et de Matériaux (SF2M), France M. Ward-Close, The Institute of Materials, Minerals and Mining (I0M3), UK J. R. Wood, The Minerals, Metals & Materials Society (TMS), USA L. Zhou, The Nonferrous Metals Society of China (NFsoc), China

National Organizing Committee:

J. Albrecht, Technische Universität Hamburg-Harburg A. Bartels, Technische Universität Hamburg-Harburg H. Baur, DaimlerChrysler M. Blum, ALD Vacuum Technologies J. Breme, Universität des Saarlandes H. J. Christ, Universität Siegen J. Eßlinger, MTU Aero Engines GmbH G. Fischer, Otto Fuchs Metallwerke G. Frommeyer, Max-Planck-Institut für Eisenforschung P. Hutmann, BMW G. Lütjering, Technische Universität Hamburg-Harburg C. Matz, Lufthansa Technik H.-P. Nicolai, Titan-Aluminium-Feinguß M. Peters, Deutsches Zentrum fur Luft- and Raumfahrt DLR K.-H. Rendigs, EADS Airbus D. Roth-Fagaraseanu, Rolls Royce Deutschland 0. Schauerte, Volkswagen P. P. Schepp, Deutsche Gesellschaft für Materialkunde H. Sibum, Deutsche Titan L. Wagner, Technische Universität Clausthal Preface

The five volumes of Ti-2003, Science and Technology are the Proceedings of the "10th World Conference on Titanium", held at the CCH-Congress Center, Hamburg, Germany, July 13-18, 2003. The conference was attended by more than 700 participants from 40 countries, and 445 papers were presented orally or as posters. Finally, 431 papers were submitted on time for publication. The seven Plenary Papers given by the representatives of the seven sponsoring countries can be found at the beginning of the Proceedings, followed by the two prospective Special Plenary Papers on "Production Technology" and "Properties and Application". The 13 topical chapters are headed by Keynote Papers with the exception of the chapter on MMCs. The papers of the Special Sessions on "A380", "Aero-Engines", and "Automotive Applications" are placed at the end of their corresponding topical chapters. For the convenience of the reader each volume contains the Author Index and the Subject Index. All papers were reviewed before publication. Special thanks go to Dr. A. Bartels, Prof. J. Breme, Prof. H. J. Christ, Prof. G. Frommeyer, Dr. M. Peters, and Prof. L. Wagner for reviewing more than 250 papers and supplying also keywords for the Subject Index. Since all papers were processed fully electronically for publication unanticipated efforts were necessary in formatting them. The patient cooperation of all authors in this time consuming effort is highly acknowledged. It should be mentioned that a large portion of the editorial workload was shared by Prof. J. Albrecht. Since no thankful acknowledgement would adequately describe and honor his devoted help it was decided that he will be coeditor of the Proceedings. Furthermore, the internal help of Mrs. U. Zimmermann and the help of the " outside" desktop publishing expert Mr. F. Reinartz in re-formatting the "easy" and "more difficult" papers, respectively, are greatly appreciated. Without their careful work the Proceedings would never have been published within this short period of time. Nevertheless, it was unavoidable that some weak points remain, mostly foreign language characters in diagrams, but at the end the emphasis was placed on publishing time rather than on further improvements by contacting the respective authors again. Finally, it should be emphasized that all members of the International and National Organizing Committees helped in the preparation of the conference which is greatly acknowledged. Thanks also to the DGM team organizing the conference including the exhibition. On July 18, 2003, the International Organizing Committee decided that the next World Conference on Titanium will be held in Japan in 2007. Congratulations to Prof. M. Niinomi and best wishes for a successful conference in Japan.

G. Lütjering Contents

Volume I

Plenary Papers

Recent Titanium Developments in the USA J. R. Wood...... 1

State of Production and Application of Titanium in the CIS I. V Gorynin, N. F. Anoshkin...... 13

Titanium Developments in the UK C. M Ward-Close...... 27

Recent Titanium Industries in Japan S. Miyamoto...... 39

Recent Developments and Applications of Titanium in France S. Marya, F. Le Maitre...... 49

The Present Situation and the Future of Titanium in China L. Zhou...... 59

Recent Developments in the Production, Application and Research of Titanium Alloys in Germany D. Helm, 0. Roder, S. Lütjering...... 69

Special Plenary Papers

Titanium Production Technology: Recent Advances and Future Needs S. P Fox, G. Terlinde...... 81

Properties and Applications of Ti: Current Status and Future Needs M. Niinomi, J. C. Williams...... 95 X Contents

Extractive Metallurgy

Keynote Paper Metallurgy of Titanium Production (Titanium Sponge, Melting, Conversion, Alloys) V Tetyukhin, D. Vinokurov...... 111

Reduction of Rutile and Ilmenite by Methane-Containing Gas and Chlorination of Titanium Oxycarbide 0. Ostrovski, G. Zhang, N. Anacleto...... 121

Potential New TiO2 Ores and TiC14 Technologies J. W. Reeves, T Tang...... 129

Application of Thermo-EMF Method during Titanium Sponge Blocks Preparation for Making Commercial Lots of Crushed Metal and for Alloys Production A. N. Petrunko, A. P Yatsenko, A. Y Andreyev, Y S. Levin, A. M. Brynza, V V Telin, V P Murashov, K. L. Feofanov...... 135

Establishment of the Manufacturing Technology of 5N Super Purity Titanium Billets by Kroll Process T Hyodo, H. Ichihashi...... 141

Implementation and Utilisation of a Mathematical Model to Simulate Vacuum Arc Remelting of Titanium Alloys A. F. Wilson, A. Jardy, J. Hamel, S. P Fox, D. Ablitzer...... 149

The Influence of VAR Processing Parameters on Solidification Behavior of Ti-6A1-4V Alloy Y T Hyun, W. Kim, H. Lee, S. E. Kim, Y. T Lee...... 157

Microscopic Segregation of Ti-6A1-4V Ingot by VAR J. L. Liu, Y Q. Zhao, L. Zhou...... 165

Manufacturing of PAM-Only Processed Titanium Alloys E. Christ, K. Yu, J. Bennett, F Welter, B. Martin, S. Luckowski...... 173

Direct Production of Ti-6A1-4V Alloy Plate from Electron Beam Cold Hearth Melted Slab Ingot J. R. Wood, J. C. Fanning...... 181

Composition Control in Hearth Melting Processes A. Mitchell...... 189 Contents XI

Modelling of the EBCHM Process for Titanium Alloys S. V Akhonin, 0. M. Kalinuk, S. L. Semiatin...... 197

An Advanced ESR Process for the Production of Ti-Slabs H. Scholz, M Blum, U. Biebricher...... 205

Electron Beam Surface Glazing of Titanium Ingots M. P. Trygub, S. V Akhonin, 0. M Pikulin, D. Fischer, K.-P. Wagner...... 213

Direct Electrowinning of Titanium: Combination of Electrolysis and Melting of Titanium Metal by DC-ESR Apparatus T Takenaka, M. Kawakami...... 221

High-Strength and Heat-Resistant Alloys with Intermetallics of MEM Technology Y Y Kompan, M. L. Zhadkevich, I. V Protokovilov, V N. Moiseev...... 229

Titanium Electrowinning M. V Ginatta...... 237

OS Process — Thermo-Electro-Chemical Reduction of TiO2 in the Molten CaC12 R. 0. Suzuki...... 245

Reduction of Titanium Oxide in Molten Salt Medium T Abiko, I. Park, T H. Okabe...... 253

Titanium Powder Production by Preform Reduction Process T H. Okabe, T Oda, Y Mitsuda...... 261

Mechanochemical Carbothermic Reduction of Ilmenite M. H. Payday, M. Raoufi...... 269

The Effect of Ball Milling on the Polymorphous Transformation of TiO2 (Anatase Type) N. Setoudeh, A. Saidi...... 277 XII Contents

Wrought Processing

Keynote Paper Development Trends of the Wrought Processing for Titanium and Titanium Alloys ( An Overview) C. Li, J. Deng...... 285

Titanium Alloy Billet Processing for Low Ultrasonic Noise M. F. X. Gigliotti, R. S. Gilmore, J. N. Barshinger, B. P. Bewlay, C. U. Hardwicke, G. A. Salishchev, R. M Galeyev, 0. R. Valiakhmetov...... 297

Premium Quality Titanium Billets Produced by a Highly Sophisticated Rotary Forging Machine D. Fischer, K.-E. Piper...... 305

Production of Large Scale Billets with Submicrocrystalline Structure out of Ti-6A1-4V Alloy Using the 3D Isothermal Forging G. A. Salishchev, S. V Zherebtsov, 0. R. Valiakhmetov, R. M. Galeyev, V K. Berdin, S. L. Semiatin...... 313

The Prediction of Microstructural Development during TIMETAL® 6-4 Billet Manufacture A. F. Wilson, V Venkatesh, R. Pather, J. W. Brooks, S. P Fox...... 321

Evaluation of Ti-6A1-4V Product Extruded Directly from Plasma Arc Melted Ingots D. Li, F. Welter; B. Martin, R. Addison, P Russo, 0. Yu...... 329

The Trial Production of Large Diameter Bar of Ti-6-22-22S Titanium Alloy S. Hui, X. Wang, Z. Li, B. Gao, Z. Zhang...... 337

Titanium Processed by Rotary-Die Equal-Channel Angular Pressing A. Watazu, Y Nishida, I. Shigematsu, J. Zhu...... 343

Production of Sheet Half-Finished Products out of Titanium with Submicrocrystalline Structure and their Mechanical Properties G. A. Salishchev, S. P Malysheva, S. Y Betsofen...... 349

Wiredrawing of Low Cost Beta Titanium (Timetal®LCB) M Jackson, R. J. Dashwood, L. Christodoulou, H. M. Flower...... 357

High Temperature Deformation Behavior of Ti12LC Alloy Y L. Li, Y. Q. Zhao, K. Y. Zhu, C. L. Liu, H. Wu, L. Feng...... 365 Contents XIII

Influence of Microstructure on Hot Plasticity of Ti-6A1-4V and Ti-5Al-5Mo-5V-1Cr-1Fe Titanium Alloys K. Kubiak, E. Hadasik, I Sieniawski, W Ziaja...... 371

The Comparison of Hot Deformation Resistance of Titanium Alloys during Hot Upsetting Y. He, S. Wei, P. Zhu...... 379

Properties Comparison for Various Beta and Alpha-Beta Alloys I. Ferrero, A. Hutt, S. Sweet...... 385

Determining Mathematics Model of Deformation Stress of Ti-Ni Alloy Z. Pan, A. P Smolin, M. Li, Z. Lian...... 393 Near Net Shape Production

Keynote Paper

New Titanium Products via Powder Metallurgy Process T. Saito...... 399

Density, Thermal Expansion and Surface Tension of Liquid Titanium Alloys Measured by Non-Contact Techniques J. Brillo, S. Schneider, I. Egry, R. A. Harding...... 411

Economic-Cost Investment Casting Technology of Titanium Alloy J. Tian, S. Xiao, Z Chen, F. Kong, Y Chen...... 419

The Evolution of Casting Titanium in China Y. L. Yan, Z. J. Liu, Y. B. Zhou...... 425

The Integration of the Bi-Lamellar Heat Treatment into the Precision Casting Process H.-P. Nicolai, C. Liesner, J. Albrecht, G. Lütjering...... 431

Thermodynamic and Kinetic Consideration of Selecting Mould Materials for Casting Titanium Alloys H. S. Ding, J. J. Guo, J. Jia, H. Z. Fu...... 439

Effects of Process Parameters on Metal-Mold Reaction of Ti and Ti-6A1-4V Alloy M.-G. Kim, S.-Y. Sung, Y.-J. Kim...... 447 XIV Contents

Factors Affecting Radiographic Detectability of Ceramic Facecoat Inclusions in Titanium Investment Castings J. D. Cotton, R. H. Bossi, H. R. Phelps...... 455

Metal Injection Molding (MIM) for Near Net Shape Manufacturing of NiTi Shape Memory Alloys E. Schüller, M. Bram, H. P Buchkremer, D. Stover...... 463

A Comparison of Ingot and Powder Metallurgy Production Routes on the Statistical Variability of the High Strength Ti-10-2-3 Titanium Alloy Tensile Properties I. C. Wallis, A. Wisbey, J. W. Brooks...... 471

New Production Techniques for Low-Cost Titanium Powder Q. W Duan, Y J. Wu, M. C. Han, L. Zhou...... 479

Near Net Shape Fabrication of Highly Porous Titanium Parts M. Bram, A. Laptev, H. P Buchkremer, D. Stover...... 487

Synthesis of PM Titanium Alloys Using Titanium Hydride Powder: Mechanism of Densification 0. M. Ivasishin, D. G. Savvakin, X. O. Bondareva, O. L. Dekhtyar...... 495

Recent Development of Titanium Powder Metallurgy in China Z. Liang, P. Chen, Y. X. Cai, Y. Liu...... 503

Updating of Technology for Titanium Hydride Powder and Powder-Based Parts Production A. Petrunko, Y Griga, V Drozdenko, E. Ter-Pogosyants, V Pavlov...... 511

The Development and Application of the Low Cost Titanium Powder for Automobile Y. J. Wu, Q. W. Duan, L. Zhou...... 517

Direct Manufacturing of Titanium Parts with Unique Properties C. Over, W Meiners, K. Wissenbach, R. Poprawe...... 525

Phase Transformations in Compositionally Graded Titanium Alloys R. Banerjee, P. C. Collins, D. Bhattacharyya, S. Banerjee, H. L. Fraser...... 533

A Study on the Microstructure of Direct Laser Fabricated Ti-6A1-4V and Ti-15V-3Cr-3Sn-3Al Alloys J. Liang, J. Mei, W Voice, X Wu...... 541

Laser Deposited Titanium for Forging Preforms D. Furrer, R. Boyer...... 549 Contents XV Component Manufacturing

Keynote Paper

Making of Structural Elements (Stamping, Welding and Joining, Machining, Surface Strengthening Inclusive of Testing) S. S. Ushkov, E. A. Karasev...... 557

Production of Submicron-Grained Ti-6A1-4V Sheets with Enhanced Superplastic Properties G. A. Salishchev, 0. R. Valiakhmetov, R. M Galeyev, F. H. Froes...... 569

Strain Characteristics of Ti6A14V Alloy Super Fine Grain Sheets under SPF Conditions I. V Levin, A. N. Kozlov, V V Tetyukhin, A. V Zaitsev, A. V Berestov...... 577

Applying Superplastic Forming Principles to Titanium Sheet Metal Forming Problems W Swale, R. Broughton...... 581

Prevention of Alpha-Casing in Ti-6A1-4V during Superplastic Forming Using Thermal Spray M. J. Tan, T Cheah, X Zhu, S. Patankar, L. Hua, K. A. Khor...... 589

Effect of Heat Treatment on Superplasticity of Forged Ti-6A1-4V Alloy M Motyka, K. Kubiak, J. Sieniawski, R. Filip...... 597

The Superplasticity of Near Beta Titanium Alloy Ti-10V-2Fe-3Al H. Z. Guo, Z. K. Yao, X Y. Zhao, Y. Tan...... 603

Application of Titanium Alloys in Sheet Metal Forming E. Doege, S. Kulp, 0. Posse, C. Sunderkötter, H. Sibum...... 611

Utilisation of Explosive Forming for Titanium Alloy Sheet C. M Wentzel, E. Carton...... 619

Forming of Long Pure Titanium Cups by Cold Multi-Stage Deep Drawing T Murao, K. Mori, Y Harada...... 627

Hot Forming Characteristics of SP -700 Titanium Alloy H. Fukai, A. Ogawa, K. Minakawa, H. Sato, T Tsuzuku...... 635

A Study on Hot Formability and Barrel Shaping Technology of Ti-451 Alloy Plate B. Zhao, Y Yang, H. Yang, Y. Li...... 643 XVI Contents

Joining of Titanium Alloy 5111 D. Baxter, 1. Wallis...... 651

Current Problems of Joinability of Titanium and Titanium Alloys H. Herold, V N Zamkov, M. Streitenberger, A. A. Slyvinsky, V P Prilutsky...... 659

Titanium Joining by Sprayed Melt in Electron Beam Furnaces B. E. Paton, M. P Trygub, H. V Zhuk...... 667

Mechanical Integrity of Diffusion Bonds Between Dissimilar Titanium Alloys M R. Bache, S. J. Tuppen, W E. Voice...... 675

Diffusion Bonding of Ti 6242 to y-TiAI Alloys B. Dogan, X Zheng, K.-H. Bohm...... 683

Diffusion Bonding Characteristics of SP-700 Titanium Alloy H. Fukai, A. Ogawa, K. Minakawa...... 691

Volume II

Component Manufacturing (cont.)

Plasma Arc Welding of Commercially Pure Titanium and Ti-6AI-4V ELI Heavy Plates H Fujii, M Masaki, F. Sakuno, Y. Takeda...... 699

The Selection of Thermocycling Treatment Types Applied to the Welded Joints of Titanium Alloys V S. Lyasotskaya, S. 1. Knyazeva, L. V Fedorova...... 707

The Influence of Hot Working Process on Mechanical Properties of Ti3A1-Ti Dual Alloy Welded by Electron Beam Welding in Vacuum Z. K. Yao, H. Z. Guo, Z S. Cui, M. L. Zhang...... 715

Investigations on Arc Welding of Titanium and its Alloys G. Rückert, N. Perry, S. Marya...... 721

Fracture and Fatigue Properties of Treated Ti-6A1-4V Plates and Magnetically-Impelled Narrow-Gap TIG Welding A. Morri, G. P Cammarota, H. Herold, M. Streitenberger...... 729 Contents XVII

Weldability of 800MPa-Class Ti-Fe-O-N Based Titanium Alloy H. Fujii, M. Ishii, Y Yamashita, T Hirata, K. Itoh, K. Satoh...... 737

Manufacture of a Titanium Clad Steel Plate by a Resistance Seam Welding Process J.-M. Doh, J.-Y Byun, K.-T Hong, J.-Y. Jung...... 745

Numerical Analysis of Heat Transfer during Resistance-Seam Welding of Titanium and Steel Plates S.-H. Chung, J.-Y. Byun, J.-M. Doh...... 753

Development of a Titanium Welding Wire for GMAW K. Toyoda, T Noda, T Shimizu, M. Okabe...... 761

Brazing of CP-Ti by Micro Spot Brazing Y Miyazawa, K. Koyama, Y Miyamoto, T Ariga...... 769

Joining by Deformation: Innovative, Practice-Relevant Fastening Technologies W Lappe, H. Sibum...... 777

Friction Stir Welding of Titanium Alloys — A Progress Update M. J. Russell...... 785

The Joints Characteristics of Friction Welded Titanium and 321 Stainless Steel S. Y Kim, W. B. Lee, J M. Koo, D. U. Kim, Y M. Yeon, C. C. Shur, S. B. Jung...... 793

Explosive Welding and Foil Cladding for Titanium Alloy Sheet E. P Carton, C. M. Wentzel...... 799

Bonding Characteristics and Effect of Heat Treatment of Explosively Welded Ti/Steel Clads A. Chiba, Y. Morizono, M. Nishida...... 807

Methods for Improving Efficiency in Turning Ti6Al4V K. Sorby, K. Tonnessen, J. E. Torjusen...... 815

Workpiece Fatigue Properties after High Speed Maching of n-Titanium Ti 15-3 C. Dindorf R. Blümke, S. Landua, C. Müller...... 823

Structural — Phase Transformation in Titanium Alloys at High-Speed Mechanical Effect M. A. Skotnikova, M. A. Martynov, S. S. Ushkov, D. A. Kastorskij...... 831 XVIII Contents

Microstructure Evolution in Shear Bands during the Chip Formation of Ti 6Al 4V C. Siemers, M. Baker, D. Mukherji, J. Rosier...... 839

Influence of Different Machining Processes on the Vanadium Concentration of Beta-Phase in Ti6Al4V L. Reissig, R. Völkl, M. .1 Mills, U. Glatzel...... 847

Bright-Shining Titanium Surfaces M. Buhlert, R. Ottensmeyer, P J. Plath...... 855

Study on Electropolishing Mechanism of NiTi Alloy W Miao, X Mi, M. Zhu, Z Gao...... 861

Surface Engineering of Titanium: An-Overview H. Dong, T Bell...... 867

Hardening of Titanium Alloys Using Concentrated Energy Beams A. I. Gordienko, I. L. Pobol, V V Ivashko...... 875

Electrical Discharge Surface Alloying of Ti-6A1-4V Using Powder Sintered WC/Co Tool Electrodes H. G. Lee, R. C. Dewes, D. K. Aspinwall, W. Voice...... 883

Corrosion of Titanium Surface-Alloyed with Nickel or Nickel-Molybdenum by High Intensity Pulsed Plasma Beams in a Simulated Flue Gas EnvironmentF. A. Bonilla, T. S. Ong, G. Alcalá, P. Skeldon, G. E. Thompson, J. Piekoszewski, A. Ostapczuk, A. Chmielewski, Z. Werner, B. Sartowska, J. Stanislawski, E. Richter ... 891

Double-Glow Discharged Plasma Non-Hydrogen Carburizing on Titanium Surface Z. X Li, J. H. Du, Z. Xu, H. Zhou, L. Zhou...... 899

Oxygen Diffusion Strengthening of Ti6Al4V Alloy in Glow Discharge Plasma B. G. Wendler, T Liskiewicz, L. Kaczmarek, B. Januszewicz, D. Rylska, S. Fouvry, A. Rylski, M. Jachowicz...... 905

Elaboration and Thermo-Kinetical Study of Titanium Oxidation Assisted by a Nd-YAG Pulsed Laser L. Lavisse, C. Langlade, P Berger, D. Grevey, A. B. Vannes...... 913

Deep Case Oxygen Hardening of Titanium Alloys and Simulation Z. X. Zhang, H. Dong, T Bell...... 921 Contents XIX

Plasma Nitriding of Titanium and Titanium Alloys C. Lugmair, R. Kullmer, A. Gebeshuber, C. Mitterer, M. Stoiber, H. Patrovsky, M. Adley...... 929

Pulsed Plasma Nitriding of Titanium and Titanium Alloys U. Huchel, S. Strämke...... 935

Fatigue Strength of Nitrided High-Strength Titanium Alloys T Morita, S. Fuchikawa, J. Komotori, M. Shimizu, K. Minakawa, K Kawasaki...... 941

A Detailed Study of the Microstructures Formed during Laser Nitriding of Ti-6A1-4V under Different Gas Atmospheres J. Kaspar, A. Luft, S. Bonss, B. Winderlich, B. Brenner...... 949

Orientation Relationships in Nitrided Titanium Alloys A. Guillou, I P Bars, I. Thibon, D. Ansel...... 957

Forming of the Surface Layer Microstructure of the Ti-6A1-4V Titanium Alloy through the Laser Alloying R. Filip, J. Sieniawski, E. Pleszakow 971

Modification of the Oxide Layer of Spark-Anodized Ti-6A1-4V by Pulsed Current R. K. Sauerbrey, B. Gollas, J. H. Albering, J. 0. Besenhard, G. Fafilek, H. Kronberger, G. E. Nauer...... 979

Tribological Properties of Ti-10V-2Fe-3Al for Aeronautic Applications A. Vecino, L Braceras, E. Erauzkin...... 987

Effect of FPB (Fine Particles Bombardment) Treatment on the Friction Coefficient of Ti-6A1-4V Alloy Y Kameyama, J. Komotori, L. Fang, K. Katahira, T Kato, Y Watanabe, H. Ohmori, E. Shimodaira...... 993

Laser Gas Alloying of Titanium — Process Technology and Wear Test Results S. Bonss, B. Brenner, H.-J. Scheibe, E. Beyer...... 1001

Wear Resistant Ceramic-Based Multilayer Coatings with Dry Lubrication Ability R. Gadow, C. C. Stahr...... 1009

Effect of Titanium Alloy Class on the Fatigue Response to Mechanical Surface Treatments L. Wagner...... 1017 XX Contents

Effect of Hybrid Surface Modification on Fatigue Properties of Ti-4.5A1-3V-2Mo-2Fe Alloy J. Komotori, M .Takagaki, M. Shimizu, A. Ogawa, K Minakawa...... 1025

Improvement of Surface Properties of Titanium Alloy by Shot Peening Y Harada, H. Kosugi, K. Mori, S. Maki...... 1031

Influence of Shot Peening Parameters on the Fretting Fatigue of Ti-6A1-4V S. A. Martinez, S. Sathish, S. Mall, M. P Blodgett...... 1039

Residual Stresses in Laser Shock Peened Ti-6A1-4V Plate A. D. Evans, A. King, T Pirling, G. Bruno, P J. Withers, C. Woodward...... 1045

Evaluation of Vibrostrenthening for Fatigue Enhancement of Titanium Structural Components on Commercial Aircraft D. II. Gane, Y. S. Rumyantsev, H. T Diep, L. Bakow...... 1053

Effects of Deep Rolling on the Fatigue Behavior of Ti-6A1-4V at Ambient and Elevated Temperatures I. Altenberger, R. K. Nalla, U. Noster, G. Liu, B. Scholtes, R. 0. Ritchie...... 1059 Microstructure Evolution

Keynote Paper

Some Recent Work on Alloy and Process Development of Ti and TiAl Alloys X Wu, M. H. Loretto, D. Hu...... 1067

Phase-Separated Microstructures in Ti-Al Binary Alloy Systems M. Doi, T Kozakai, T Koyama, S. Naito...... 1075

A Quantitative Description of Multicomponent Growth of Needle-Shaped Precipitates in Non-Ideal Solutions P E. J. Rivera-Diaz-del-Castillo, S. van-der-Zwaag...... 1083

Modelling of Phase Transformation Kinetics in Ti Alloys L. Héricher, B. Appolaire, E. Aeby-Gautier...... 1091

Effect of Fe and 0 on the Continuous Cooling Beta to Alpha Transformation Behaviors of Pure Ti M. S. Oh, J. K. Park...... 1099 Contents XXI

Phase Stability of Ti-Fe-O-N Based Titanium Alloys at Intermediate Temperature H. Fujii, K. Takahashi, M. Ishii, A. Kawakami...... 1107

Effect of Carbon on the Distribution of Alloying Elements and Microstructure of Ti-5.6Al-4.8Sn-2Zr-1Mo-0.35Si-1Nd Titanium Alloy S. Z. Zhang, Q. J. Wang, G. P Li, Y. Y. Liu, D. Li, R. Yang...... 1115

On Phase Relationship between Ti-Si Precipitates and Beta Matrix of Ti-6Al-4Fe-(0.1 to 1.0)Si Alloys B.-H. Choe, J.-H. Choi, H.-W. Jeong, Y.-T. Hyun, S.-E. Kim, Y-T Lee...... 1123

Experimental Study and Computer Modeling of the Isothermal Beta to Alpha Transformation Kinetics in Titanium Alloys P E. Markovsky, S. Malinov, W Sha...... 1131

Microstructural Characteristics of Ti-Base Biomedical Shape Memory Alloys T Inamura, Y Fukui, H Hosoda, K. Wakashima, S. Miyazaki...... 1139

A Study on Microstructure of Solution Treated and Aged SP-700 Titanium Alloy H. Fukai, A. Ogawa, K. Minakawa...... 1147

Anisothermal Alpha Phase Formation in Ti-6.8Mo-4.5Fe-1.5Al M. Gheorge, J. I. Qazi, H. J. Rack...... 1155

Electrical Resistivity Changes during Isothermal Aging in Ti-10V-2Fe-3Al Alloy Y. Sugiura...... 1163

Prediction of the Kinetics of the Phase Transformations and the Associated Microstructure during Continuous Cooling in the Ti17 J Da Costa Teixeira, L. Héricher, B. Appolaire, E. Aeby-Gautier, G. Cailletaud, S. Denis, N. Spath...... 1171

Metastable Nano-Structure of Beta-Ti Alloys with Tweed or Tweed-Like Modulation B. H. Choe, T H. Lee, C G. Lee, S. J. Kim, Y. T. Hyun, S. E. Kim, Y T Lee...... 1179

The Microstructural Sensitivity of Ti-10V-2Fe-3Al during Isothermal Forging at Subtransus Temperatures M. Jackson, R. J. Dashwood, L. Christodoulou, H M Flower...... 1187

Microstructure of Ti-B19 High Strength Titanium Alloy J. Chen, H. Chang, H. Li, H. Yang...... 1195 XXII Contents

Resistivity Change with Room Temperature Rolling of Commercially Pure Titanium Plates S. Komatsu, M. Ikeda, T Sugimoto, M Nakagawa...... 1203

Texture and Microstructure Evolution during Recrystallization of Cold-Rolled Titanium N. Dewobroto, N. Bozzolo, T. Grosdidier, F. Wagner...... 1211

Microstructure Formed by Hot Deformation in a Near P Titanium Alloy T Furuhara, Y Toji, T Maki...... 1219

Precipitation and Recrystallization Behavior of Cold-Deformed Beta Titanium Alloys during Continuous Heat Treatment 0. M. Ivasishin, P E. Markovsky, 0. P Karasevska, Y V Matviychuk, S. L. Semiatin...... 1227

Refinement of β Grain Size Due to TiB or Y203 Precipitates in Titanium Alloy T Nomura, N. Yamamoto, T Narushima, T Iguchi, C. Ouchi...... 1235

Strain-Path Effects on Microstructure Evolution during the Hot Deformation of Ti-6Al-4V R. M Poths, B. P Wynne, W M Rainforth, S. L. Semiatin, J. H. Beynon...... 1243

Alpha-to-Beta Phase Transformation in Two-Phase Ti Alloys during Superplastic Deformation J. Koike...... 1251

Characterization of Electron-Beam Melted Ti-6A1-4V Alloy in Cast and Thermomechanically-Processed Conditions 0, M. Ivasishin, V N. Zamkov, P E. Markovsky, A. N. Kalinyuk, R. V Teliovich, S. L. Semiatin...... 1259

Experimental and Multiscale Simulative Investigations of Microstructural Evolution of a Ti-6Al-4V Alloy during Thermomechanical Processing Z. X Guo, R. Ding...... 1267

Recrystallization Textures in a Ti-6A1-4V Sheet for Different Cold Rolling Conditions H. Francillette, P Petit...... 1275

Texture Development under Plane Strain Compression in Ti-6-4 R. W Evans, W J. Evans, T Smith, A. Wilson...... 1283 Contents XXIII

Texture and Microtexture Analysis of an IM I 834 Alloy after Thermo-Mechanical Processing L. Germain, N. Gey, M. Humbert, P Bocher, M. Jahazi...... 1291

Texture Evolution during Primary Processing of Production-Scale Vacuum Arc Remelted Ingots of Ti-6A1-4V M. G. Glavicic, P A. Kobryn, R. L. Goetz, K. 0. Yu, S. L. Semiatin...... 1299

Experimental Investigation and 3D Monte-Carlo Simulation of Texture-Controlled Grain Growth in Titanium Alloys 0. M Ivasishin, S. V Shevchenko, P E. Markovsky, S. L. Semiatin...... 1307

Polycrystalline Modelling of Forging in β Phase Field of Ti 17 .1 Delfosse, C. Rey, N. Späth...... 1315

Influence of Cold Rolling on Phase Transformations and Texture in a Beta Titanium Alloy I. Thibon, F Prima, G. Texier, T Gloriant, D. Ansel...... 1323

Inhomogeneous Texture and Microstructure Formation in High Speed Hot Rolling of Ti-15V-3Cr-3Sn-3Al Alloy T Sakai, F. Kitano, Y Saito...... 1331

Phase Transformation Textures and Microtextures in TIMETAL-21S Titanium Alloy Z. S. Zhu, H. Inoue...... 1339

Influence of Heat Treatments on Texture and Microstructure Evolution in Rolled Sheets of a β-Cez Alloy C. Quesne, M. H. Mathon, T Baudin, R. Penelle...... 1345

Beneficial Effects of Hydrogen as a Temporary Alloying Element on Processing and Properties of Titanium Alloys O. N Senkov, F. H. Froes...... 1353

Hydrogen Diffusion in Beta Titanium Alloys H.-I. Christ, M Decker, G. Lohse, S. Schroers...... 1361

The Dilatometer to Estimate the Transformations in Ti6Al4V Alloy during Nitrogen Absorption G. Greno, R. Gerosa, B. Rivolta, G. Silva...... 1369 XXIV Contents Volume III

Properties

Keynote Paper Relationships between Texture, Microstructure and Properties in Titanium and some Titanium Alloys R. Penelle, T Baudin, C. Quesne...... 1377

A Combinatorial Approach to the Development of Neural Networks for the Prediction of Composition-Microstructure-Property Relationships in α/β Ti Alloys P C. Collins, S. Connors, R. Banerjee, H. L. Fraser...... 1389

An Integrated Approach to the Calculation of Materials Properties for Ti-Alloys N. Saunders, X Li, A. P Miodownik, .1-P. Schille...... 1397

Research on the Intelligent Approach of Material Property Prediction and Optimization H. Y Yang, Q. H. Le, Y Q. Zhao...... 1405

Modeling the Relationships between Microstructural Parameters and the Tensile Properties in Ti-6Al-4V Using Neural Networks and Fuzzy Logic Models J. S. Tiley, R. Banerjee, T Searles, S. Kar, H. Fraser...... 1413

Elastic Constant Measurements of Ti Alloys Using Resonant Ultrasound Spectroscopy T. J. Ulrich, D. Chandra, A. Imam...... 1421

Effect of Texture and Deformation Temperature on the Strain Hardening Response of Polycrystalline a-Titanium A. A. Salem, S. R. Kalidindi, R. D. Doherty, M. G. Glavicic, S. L. Semiatin...... 1429

Extraordinary Properties of Bulk Ultrafine-Grained CP Ti Processed by Severe Plastic Deformation V V Stolyarov, R. Z. Valiev, L. Zeipper, G. Korb...... 1437

Nanostructuring of Titanium Based Materials by Severe Plastic Deformation — Fundamentals and Application L. Zeipper, G. Gemeinböck, G. Korb, M. Zehetbauer, E. Schaller, B. Mingler...... 1445

The Effect of Microstructure on the Dynamic Deformation Behavior of Ti-6A1-4V Alloy C. S. Lee, D.-G. Lee, Y H. Lee, S. Lee, S. M. Hur...... 1453 Contents XXV

Numerical and Microstructural Evaluation of Elevated Temperature Compression Tests on Ti-6Al-4V E.-L. Westman, R. Pederson, B. Wikman, M. Oldenburg...... 1461

In Situ (SEM) Tensile Test of an α/β Titanium Alloy: Analysis and Evolution of Activated Slip Systems F. Bridier, P Villechaise, J. Mendez...... 1469

The Response of TIMETAL® 6-4 and TIMETAL®-550 to Medium and High Strain Rate Deformation M. Zakaria, M. H. Loretto, A. Wilson, W. Voice, X Wu...... 1477

Damage Mechanisms of PM Ti-6Al-4V at Cryogenic Temperature S. Di Iorio, L. Briottet, E. F Rauch, D. Guichard...... 1485

Analysis on Relationship between Strain Behavior and Microstructure of CT20 Titanium Alloy at 20K Y Du, X Cai, G. Yang...... 1493

Microstructure and Properties of a Nd-Containing High-Temperature Titanium Alloy S. Q. Li, R. M. Liu...... 1499

Investigation of Stress Distribution in α+β Titanium Alloy by FEM W Ziaja, J. Sieniawski, M. Motyka...... 1505

Tensile Property of a" Martensite Structure in Ti-8mass%Mo Alloy Y Mantani, Y. Takemoto, M. Hida, A. Sakakibara...... 1511

Development of Multi Functional Titanium Alloy, "GUM METAL" T Furuta, K. Nishino, J. H. Hwang, A. Yamada, K. Ito, S. Osawa, S. Kuramoto, N. Suzuki, R. Chen, T Saito...... 1519

Origin for "Super" Properties in GUM METAL S. Kuramoto, T Furuta, J. H. Hwang, Y. Seno, T Nonaka, H. Ikehata, N. Nagasako, K Nishino, T Saito, C. Iwamoto, Y. Ikuhara, T Sakuma...... 1527

Phase Transformations and Mechanical Response in a Ti/Mo-Based Pseudo-Elastic Alloy T Zhou, M. Aindow, S. P Alpay, M. J. Blackburn, M H. Wu...... 1535

Mechanical Properties and Microstructures of Pseudoelastic Beta Ti-Mo-V-Nb-Al Alloys M H. Wu, P A. Russo, J. G. Ferrero...... 1543 XXVI Contents

Phase Transformation and Mechanical Properties of a New ß Titanium Alloy with Low Elastic Modulus G. J. Yang, T Zhang...... 1551

The Effect of Heat Treatment on the Microstructure of Ti-5Al-5Mo-5V-3Cr- I Fe (Ti-555) M. Harper, R. Williams, G. B. Viswanathan, J. Tiley, R. Banerjee, D. J. Evans, H. L. Fraser...... 1559

The Supersaturated Beta Phase with Tweed Structure and its Mechanical Properties of Beta Ti Alloys Y T Lee, H. W Jeong, Y T Hyun, S. E. Kim, D. S. Ro, B. H. Choe...... 1567

Microstructure and Mechanical Properties of a New Near Beta Titanium Alloy — Ti-B19 H. Chang, J Chen, L. Zhou...... 1575

The Influence of Al Content on Tensile Properties and Aging Behavior of Ti-4.3Fe-7.1Cr-Al Alloys M. Ikeda, S. Komatsu, M. Ueda, K. Inoue, A. Suzuki...... 1583

Effect of Heat Treatment on Mechanical Properties of a New Metastable Beta Titanium Alloy P Ge, Y Q. Zhao, L. Zhou...... 1591

Analysis of the Mechanical Behavior of Metastable ß Titanium Alloys — Influence of the Phase Transformation M Khelifa, E. Aeby-Gautier, S. Denis, P Archambault, J. P. Sarteaux...... 1599

Aging Behaviors from Metastable Beta Matrix and Mechanical Properties of Ti-15-3 Alloy B.-H. Choe, S.-J. Kim, Y-T Lee, M. Hagiwara...... 1607

Fracture Characteristics of Forged Plate of Ti-4.5Al-3V-2Mo-2Fe Conducted with Single and Duplex Annealing in a+ß Field Gunawarman, M Niinomi, D. Eylon, S. Fujishiro, C. Ouchi...... 1615

An Investigation of Near Beta Forging for Titanium Alloys and the Engineering Application Y. G. Zhou, W. D. Zeng, H. Q. Yu...... 1623

Influences of Chemistry and Processing on Microstructure and Mechanical Properties for Ti-6Al-2Sn-2Zr-2Cr-2Mo-0.15Si E. Christ, P Russo, H. Phelps, L. Clark...... 1631 Contents XXVII

Microstructures and Mechanical Properties of Ti-6-22-22s Alloy Step by Step Rolling Rod H. Li, Y Zhao, H. Qu, L. Feng, Zhang, H. Yang...... 1639

Effect of Heat-Treatments on Microstructures and Properties of Ti-6-22-22S Alloy L. Feng, Y Q. Zhao, H. L. Qu, H. Li, H. Y Yang, Z S. Zhu...... 1645

The Effect of Duplex Aging on the Tensile Behavior of Ti-35Nb-7Zr-5Ta-(0.06-0.7)O Alloys J. I. Qazi, V Tsakiris, B. Marquardt, H J Rack...... 1651

Fracture Toughness Mechanisms of High Strength ß Titanium Alloys M. Benedetti, J. 0. Peters, G. Lütjering...... 1659

Wear of Ti-6A1-4V Alloy under Constant and Variable Fretting Conditions: Development of an Energy Wear Approach P Duo, C. Paulin, S. Fouvry, P Perruchaut...... 1667

Prediction of Ti-6A1-4V Crack Nucleation under Fretting Loadings: Impact of the Size Effect S. Fouvry...... 1675

Fretting Fatigue and Frictional Wear Characteristics of High Workable Titanium Alloy, Ti-4.5Al-3V-2Mo-2Fe J. Takeda, M Niinomi, T Akahori...... 1683

Reciprocating Sliding Wear Resistance of ß21 SRx Titanium M. Long, J. I. Qazi, H. J Rack...... 1691

Oxygen Diffusion in Titanium and its Abrasive Wear S. Kral, Z. Zalisz...... 1699

Characteristics and Effects of Pad Alloys and Cu-Ni Coating on Fretting Fatigue Behavior of Ti-6A1-4V A. L. Hutson, M Niinomi, E. Shell, D. Eylon...... 1707

Hydrogen-Induced Microstructure Changes in Ti-6A1-4V Alloy E. Tal-Gutelmacher, D. Eylon, D. Eliezer...... 1715

Hydrogen Effects on the Mechanical Properties of Beta Titanium Alloys G. M. Lohse, A. Senemmar, H-J. Christ...... 1723 XXVIII Contents

Effect of Hydrogen and Tensile Strain Rate on Hydrogen Embrittlement of Ti-2A1-2.5Zr Alloy L. Yang, G. J. Yang, S. Y. Qiu, Y R. Jiang...... 1731

Hydrogen Effects of ß-21S Titanium Alloy E. Tal-Gutelmacher, D. Eliezer, E. Golan, E. Abramov...... 1737

Effect of Grain Size on Fatigue Properties in Ti-5%A1-2.5%Sn ELI Alloy Y Ono, T Yuri, H. Sumiyoshi, S. Matsuoka, T Ogata...... 1745

Comparison of Accumulated Damange in Low Cycle and High Cycle Fatigue Conditions J. Frouin, S. Sathish, J. Maurer, D. Eylon, J. K. Na...... 1753

Texture, Microstructure and Mechanical Properties in TIMETAL® 6-4 W J. Evans, R. W. Evans, M T Whittaker, W Voice...... 1759

Effects of Microstructure on the High Cycle Fatigue Behaviour of Ti-6A1-4V Alloys K Taylor, P Bowen, D. Rugg...... 1767

Influential Factors on Interior-Originating Fatigue Fractures of Ti-6A1-4V in Gigacycle Region: Focusing on Stress Ratio and Internal Environment of Material T Nakamura, H. Oguma, T Shiina...... 1775

The Effect of Microstructures on Interior-Originating Fatigue Fractures of Ti-6A1-4V in Gigacycle Region H. Oguma, T Nakamura...... 1783

Thermographic Characterization of Fatigue Damage in Ti-6Al-4V H. Roesner, N. Meyendorf D. Eylon...... 1791

Localized Damage Characterization in Fatigue Fractured Ti-6Al-4V Using Nonlinear Acoustics and Transmission Electron Microscopy I Frouin, J. Maurer, S. Sathish, D. Eylon, J. K. Na...... 1799

Tension and Torsion Fatigue Response of TIMETAL ® 6-4 and TIMETAL® 550 Alloys W J. Evans, J. P Jones, P Crofts...... 1807

Cycle Deforming Behavior and Microstructure Observation of Ti-2A1-2.5Zr Alloy at 350°C Z T Yu, L. Zhou, J. Deng...... 1815 Contents XXIX

Influence of Prior Deformation on the Development of Duplex Microstructures and Fatigue Stengths in Ti-6242 J. Zhang, J. Lindemann, L. Wagner...... 1823

Deformation and Crack Initiation in Ti-6242Si Alloys B. Dogan, X Zheng, U Lorenz, A. Ankara...... 1831

Comparison of Microstructure and Mechanical Properties of Die-Forged Aero Engine Compressor Disk Alloys Ti-6242, Ti-6246 and Ti-17 0. Roder, D. Helm, S. Lütjering, G. Fischer, G. Terlinde, T Witulski...... 1839

Mechanical Properties of SP-700 Titanium Alloy at Room Temperature H. Fukai, A. Ogawa, K. Minakawa...... 1847

Influence of Heat Treatment on Mechanical Properties of Beta 21SF. Busongo, K Imtiaz, G. Lütjering...... 1855

Heat Treatment and Property of Beta-21S Bar W. Ye, X Tuo...... 1863

Mechanical Properties of Beta Processed Ti-6246 T Krull, C. Sauer, G. Lütjering...... 1871

Microstructure and Mechanical Properties of ß-Annealed Ti-6246 V Bondarchuk, G. Lütjering...... 1879

Incorporating Variability in a Mechanism-Based Life Prediction Methodology for Fatigue of Ti-6Al-2Sn-4Zr-6Mo S. K. Jha, J. M Larsen, A. H. Rosenberger...... 1887

Role of Microstructure in Crack Nucleation and Fatigue Life of the Beta Titanium Alloy: Ti-10V-2Fe-3Al S. K. Jha, K. S. Ravi Chandran...... 1895

A Microcrystallographic Study of Fatigue Damage in Ti-Ni Shape Memory Alloy N. I. Zahari, M. Sugano, M. A. Imam, Z Tanaka, T Satake...... 1903

Short-Fatigue-Crack-Growth Phenomena in a Beta-Titanium Alloy W Floer, U Krupp, H.-J. Christ, A. Schick, C.-P. Fritzen...... 1911 XXX Contents

Effect of a Grain Size Gradient on the Profile and the Propagation of Short Surface Cracks in Titanium Grade 2 C. Müller...... 1919

Effect of Aging on Fatigue-Crack Growth Behavior of a High-Temperature Titanium Alloy J. R. Liu, S. X. Li, D. Li, R. Yang...... 1925

Fatigue Crack Growth Behaviour in Titanium Single Crystals S. Ando, Y. Mine, H. Tonda, K. Takashima...... 1933

Crack Damage Characterization in Ti-6A1-4V by Surface White-Light Profilometry J. Schroeder, N Meyendorf, E. B. Shell, D. Eylon...... 1941

In-Situ Studies of Deformation Behavior and Damage Evolution in High-Temperature Titanium Alloy IMI 834 G. Biallas, H. J. Maier...... 1949

Crack Growth Resistance of Sharply Gradiented Microstructures .1 Heidemann, M Benedetti, J. 0. Peters, G. Lütjering...... 1957

Crack Propagation and its Computation in Graded Microstructures of a Near-a-Titanium Alloy C. Müller, B. Burghardt...... 1965

Molecular Dynamics Simulation of Crack Propagation in Titanium S. Ando, Y. Mine, K. Takashima, H. Tonda...... 1973

Influence of Variable Amplitude Loading on Fatigue Crack Propagation Behavior of Ti-6Al-4V E. Notkina, G. Lütjering, R. 0. Ritchie...... 1979

Low-Cycle Dwell-Time Fatigue in Ti-6.5Al-3.5Mo-1.5Zr-0.3Si Titanium Alloy Y. H. Yu, W. D. Zeng, Y. G. Zhou...... 1987

Crack Propagation under Fatigue-Corrosion Interaction in Titanium Alloys C. Sarrazin-Baudoux...... 1995

Interactions between Fatigue, Creep and Environmental Damage in Ti6242 W .1 Evans, B. Ford, .1 P Jones, S. Williams...... 2003 Contents XXXI

Recovery of Strain Hardening at Low Temperatures in Alpha Ti-6A1 and Ti-6242 M. C. Brandes, M. J. Mills...... 2011

Ambient Temperature Creep Deformation Behavior of an Alpha-Ti-1.6 Wt.% V Alloy A. K. Aiyangar, B. W Neuberger, S. Ankem...... 2019

Study of Creep Mechanisms and Precipitated Particle Role of Ti-600 Alloy Q. Hong, Y L. Qi, Y Q. Zhao, G J. Yang...... 2027

Effects of Alloying and Cold-Work on Anisotropic Biaxial Creep of Titanium Tubing K. L. Murry...... 2033

Volume IV

Environmental Behavior

Keynote Paper Corrosion, Oxidation and Surface Modification of Titanium Alloys J. Shen, X Wan, Z. Li...... 2041

Growth Behaviors of Alpha Cases in Ti-6Al-4V and Ti-10V-2Fe-3Al Alloys during High Temperature Heat Treatment in Air Y. Sugiura...... 2051

Improvement of Oxidation Resistance of Ti-Based Alloys with Silicon D. Vojtech, T Kubatík, B. Bártová...... 2059

Oxidation and Stress Enhanced Oxidation of Ti-6-2-4-2 P. W M. Peters, J. Hemptenmacher, C. Todd...... 2067

Corrosion Resistance of Ti-Nb Alloys D. Zander U. Koster; M. Andrei, P L. Bonora...... 2075

Stress-Corrosion and Corrosion Fatigue Cracking in Ti-5111 and VLI Ti-6Al-4V P S. Pao, M A. Imam, S. J. Gill, C. R. Feng, R. A. Bayles...... 2083

Sustained Load Cracking in Titanium Alloys A. Kostrivas, L. S. Smith, M. F. Gittos...... 2091 XXXII Contents

Comparative Corrosion Resistance of Commercial Ru- and Pd-Modified C. P. Titanium Alloys R. W Schutz, R. L. Porter...... 2099

PGMA — A Novel Corrosion Protection Method for Titanium J. S. Grauman...... 2107

Nitridation of Titanium-Tin Alloys during Heating in Air T Narushima, K. Suzuki, S. Kimura, Y Iguchi, C. Ouchi...... 2115

Intermetallics

Keynote Paper Processing and Application of Engineering γ-TiAl Based Alloys H. Clemens, F. Appel, A. Bartels, H. Baur, R. Gerling, V Güther, H. Kestler...... 2123

Microstructure-Property Relationships in Newly Developed Multiphase Ti

2AlNb-Based Titanium Aluminides L. Germann, D. Banerjee, I Y Guédou, J.-L. Strudel...... 2137

The Grain Boundary Character Distribution in BCC and O+BCC Ti-Al-Nb Alloy Microstructures C. J. Boehlert, S. Civelekoglu, R. C. Gundakaram, J. F Bingert...... 2145

B2 Grain Size Refinement of (O+B2) Ti-22Al-27Nb Alloy S. Emura, A. Araoka, M Hagiwara...... 2153

The Role of W in Orthorhombic Ti2AlNb Based Intermetallic Alloy for the Enhancement of Creep Properties above 700°C S. J. Yang, S. W Nam, M Hagiwara...... 2161

Composition and Microstructure Analysis of Ti-24Al-17Nb-0.5Mo Alloy after YAG Laser Surface Remelting Treatment J. Y. Li, Z. C. Feng, Z. L. Li, R. Yang...... 2169

Bulk Properties of Ti2AlNb from First Principles Calculations Q. M. Hu, R. Yang, Y. L. Hao, D. S. Xu, Y Y Liu, D. Li, W T. Wu...... 2177

High Speed Milling and Surface Grinding of an Orthorhombic TiAl Alloy Ti-23Al-25Nb I Simao, D. K. Aspinwall, R. C. Dewes, W Voice...... 2185 Contents XXXIII

Compaction of Mechanically Alloyed Ti-Si Intermetallics Coated with Titanium: Influence of the InterfaceF. Simões, B. Trindade...... 2193

Pressurized Reaction Sintering of Intermetallic Compound of TiAl Using Resistance Heating as Ignition S. Maki, Y. Harada, K. Mori...... 2201

A New Processing Route for Titanium Alloys by Aluminothermic Reduction of Titanium Dioxide and Refining by ESR J.-C. Stoephasius, B. Friedrich, J. Hammerschmidt...... 2209

Comparison of Microstructure and Phase Composition of Vacuum Induction Ti-48Al-2Cr-2Nb Alloy Melted in Crucibles with Plasma Spaying Coatings J. Chraponski, W Szkliniarz, T Mikuszewski...... 2217

The Chemical Composition, Structure and Properties of Gamma-TiAl Intermetallic Phase Based Alloys Melted in Vacuum Induction Furnaces in Ceramic Crucibles W Szkliniarz, T Mikuszewski, I Chraponski, B. Juszczyk, A. Koscielna...... 2225

A Study on the Metal-Mold Reaction for TiAl Investment Casting S. Y. Sung, M. G. Kim, Y.J. Kim...... 2233

Development of Gamma Alloy Based on Ti-46.5Al-5Nb for Cast Applications Y. Y. Cui, H. F. Xiang, L. M. Dong, S. X Li, R. Yang...... 2241

Enhanced Superplasticity of Fine-Grained Gamma TiAl (Mo, Cr, Si) Alloys G. Frommeyer, S. Knippscheer...... 2249

Development of Novel Sheet Rolling Process of Ingot-Metallurgy γ-TiAl+α2-Ti3A1 Based Alloys for Production of Sheets with Enhanced Mechanical Properties V M Imayev, R. M Imayev, A. V Kuznetsov...... 2257

The Joints Properties of TiAl and AISI4140 by Friction Welding Method W B. Lee, J. M. Koo, M. G. Kim, S. Y. Sung, Y. J. Kim, S. B. Jung...... 2265

Study on Joining of Titanium Aluminide Intermetallic Alloy and Steel T Shinoda...... 2271

Microstructure and Properties of y TiAl Sheet Joints Brazed with a Ti-Cu-Ni Alloy I. C. Wallis, H. S. Ubhi, M.-P. Bacos, P Josso, J. Lindqvist, D. Lundstrom, A. Wisbey...... 2277 XXXIV Contents

Process Development and Quality Evaluation of Large Size Wrought Plates from Titanium Intermetallide Base Alloy (γ-Alloy) V V Tetyukhin, I. V Levin, A. S. Shibanov, I. U. Puzakov, A. V Bobrov...... 2285

Studies on the Conventional Machining of TiAl-Based Alloys E. Uhlmann, G. Frommeyer, S. Herter, S. Knippscheer, J. M. Lischka...... 2293

Modelling of the Deformation Behaviour of Intermetallic γ-TiAl-Based Alloys —A Short Review D. Fischer, T Schaden, H. Clemens, W Marketz...... 2301

Integrated Material System for P/M Nanocrystalline TiAl H. Kimura, T Uchino...... 2309

Novel Approaches to Thermomechanical Processing of Ingot-Metallurgy y- TiAl Based Alloys R. Imayev, V Imayev, A. Kuznetsov, M Oehring, U. Lorenz, F. Appel...... 2317

Development and Control of Feathery Microstructure in Cr Added TiAl Alloys K. Niinobe, Y Tomota...... 2325

Effects of Ternary Alloying Elements on Constitution and Mechanical Properties of TiAl Base Alloys S. Knippscheer, G. Frommeyer...... 2331

Titanium Boride Clusters and their Effect on Tensile Properties in TiAl Alloys D. Hu...... 2339

Effects of Boron, Carbon and Gadolinium Additions on the Microstructure and Grain Size of Ti-48Al-2Cr-2Nb Alloy W Szkliniarz, T Mikuszewski, J. Chraponski, B. Juszczyk, A. Koscielna...... 2347

Refinement of the Lamellar Structure in TiAl Based Alloys by Addition of Rare Earth Elements Y Chen, F. Kong, Z. Chen, J. Tian...... 2355

Microstructure and Mechanical Properties of Multi-Oriented Columnar TiAl Alloys S. E. Kim, Y T Lee, M. H. Oh, H. Inui, M. Yamaguchi...... 2361

Microstructure and Properties of Quenched and Aged TiAl Alloys D. Hu...... 2369 Contents XXXV

On the Mechanical Behavior and Microstructural Evolution of a TiAl Alloy under Quasistatic and Dynamic Compression S. Aurélio, A. Redjaïmïa, E. Lach, A. Lichtenberger...... 2377

Texture Formation during Hot-Rolling of γ-TiAI W Schillinger, A. Bartels, R. Gerling, H. Clemens...... 2385

Influence of the Changes in the Microstructure of a Nb-Containing TiAl Alloy on the Measurements of Internal Friction M Perez-Bravo, M. I. No, L Madariaga, L Hernández, K. Ostolaza, J. San Juan...... 2393

Creep Properties and Texture of a High Niobium Containing γ-TiAI Sheet Material S. Bystrzanowski, A. Bartels, R. Gerling, F. P. Schimansky, H. Clemens, H. Kestler, G. Dehm, M. Weller...... 2401

Foreign Object Damage (FOD) and Fatigue Performance of a Gamma Titanium Aluminide at Service Temperatures M. R. Bache, W E. Voice...... 2409

Comparison of the High-Temperature Fatigue Behaviour of Two Different Gamma-TiAl Sheet Materials: Influence of a High Niobium Content P Schallow, H.-J. Christ...... 2417

Notch Effects on HCF Strength of Gamma Titanium Aluminides J. Lindemann, D. Roth-Fagaraseanu, L. Wagner...... 2425

Friction and Wear Performance of a Thermal Oxidation Treated Titanium Aluminide J. Xia, C. X Li, H. Dong, T Bell...... 2433

Environmental and Thermal Protection of Gamma Titanium Aluminides C. Leyens, R. Braun, M Peters...... 2441

Oxidation Activation Energy of TiAl Intermetallics H L. Qu, L. Zhou, H. R. Wei, Y. G. Zhou, Y Q. Zhao, W D. Zeng...... 2449

MCrAlY Coatings for the Protection of Gamma Titanium Aluminide J. D. Béguin, J. Alexis, D. Adrian, S. Metayer, T Masri, J. A. Petit, P Belaygue...... 2455 XXXVI Contents

MMCs

Titanium Matrix Composites (TMC) Status W M. Hanusiak, J. L. Fields, D. S. Nansen...... 2463

Potentials of Orthorhombic Titanium Aluminide Composites A. Vassel, f. Pautonnier, M. Raffestin...... 2471

Interfacial Reaction of Super α2 and Ti2AlNb Composites Reinforced by SCS-6 SiC Fibers Y Q. Yang, Y. Zhu, Z. J. Ma, Y. Chen...... 2479

Metallurgical Features Related to Liquid Route Ti Alloy Coating of C Coated SiCcvd Filaments C. Duda, C. Arvieu, J.-F. Fromentin, J.-M. Quenisset...... 2487

Microstructures of "In Situ" Ti/TiBw Composites Produced by a Liquid Manufacturing Route Dartigues, S. Payan, M. Garcia de Cortázar, I Coleto, J. Gall, F Lepetitcorps...... 2495

A Powder Coated Fibre Pre-Processing Route for Cost Effective Production of Ti/SiC Metal Matrix Composites Z. X. Guo, N R. F. Beeley...... 2503

Innovative Processing of Porous Ti Composite by Combustion Reaction M Kobashi, N. Kanetake...... 2511

Influence of TiC Particle on Microstructures and Properties of Titanium Matrix Composite Y. L. Qi, Y. Q. Zhao, L. Y. Zeng, X. N. Mao...... 2517

Titanium as an Activator Material for Producing MMCs by Pressureless Melt Infiltration K. Lemster, U. E. Klotz, S. Fischer, P Gasser, J. Kübler...... 2523

Hot Formability of a Particle Reinforced Ti-Alloy C. Poletti, W Marketz, H. P Degischer...... 2531

Properties of Diffusion Bonded TiC Particulate Reinforced Ti-6Al-4V Metal Matrix Composite A. A. M. da Silva, J. F. dos Santos, T R. Strohaecker, A. Reguly...... 2539 Contents XXXVII

Direct Laser Deposition of In Situ Metal Matrix Composites Based on Titanium Borides R. Banerjee, P C. Collins, A. Genc, J. Tiley, H. L. Fraser...... 2547

Phase Equilibria and Phase Transformations in the Ti-Rich Corner of the Ternary System Ti-Fe-B F. Aubertin, M. Hamentgen, M. Bram, J Breme...... 2555

The Effects of Holding at Temperature on Fracture Mechanism of Titanium Based Metal Matrix Composite M. J. Hadianfard...... 2563

Debonding Criterion in the Push-Out Process of Fiber-Reinforced Titanium Matrix Composites W D. Zeng, Y G. Zhou, P W. M. Peters...... 2569

Quantitative Analysis of the Fatigue Damage of Ti-6242/SCS-6 Metal Matrix Composite D. Bettge, B. Günther, W. Wedell, P D. Portella, J. Hemptenmacher, P W M. Peters...... 2577

Thermo-Mechanical Fatigue Failure and the Life Prediction of a Unidirectionally Reinforced SP-700/SCS-6 Composite M. Okazaki, Y Yamazaki, K. Hirano, K. Minakawa...... 2585

The Way of Optimization of the Fatigue Resistance of Titanium Matrix Composites — Models and Experiments J. M Hausmann, C. Leyens, W A. Kaysser...... 2593

Mechanical Properties of TiB Ceramic Particulate-Reinforced Ti-22A1-27Nb Alloy M. Hagiwara, S. Emura...... 2601

Study on TiC Particle Reinforced Titanium Matrix Composite L. Y Zeng, Y Q. Zhao, P S. Zhang, L. Zhou, A. Passel...... 2609 XXXVIII Contents Aero-Vehicle Applications

Keynote Paper

Titanium for Airframe Applications: Present Status and Future Trends R. R. Boyer, J. D. Cotton, D. J. Chellman...... 2615

Fabrication and Evaluation of Titanium Aluminide (Ti-Al) Honeycomb Structures for Use in Various Hypersonic and Other Aerospace Vehicles R. Leholm, A. Gurney, P Kukuchek, K. Jata...... 2627

Use of Titanium Castings on the F/A-22 Raptor — Lessons Learned H. R. Phelps, J. D. Cotton, A. Patterson, D. I Chellman...... 2635

Properties of TIMETAL 555 — A New Near-Beta Titanium Alloy for Airframe Components J. C. Fanning, R. R. Boyer...... 2643

Lap and Butt Joining by a CO2 Laser of Titanium Alloys for Civil and Military High Speed Aircraft E Caiazzo, F. Curcio, G. Daurelio, F Memola Capece Minutolo, R Ottonelli...... 2651

Special Papers: A380

Titanium Products Used at AIRBUS K.-H. Rendigs...... 2659

Titanium for Damage Tolerance Applications on A380 N. Duret...... 2667

Development of Superplastic Forming and Diffusion Bonding Titanium Alloy Aerospace Components Y. Marchal, D. Gueuning, S. Quets...... 2673

Contribution to the Introduction of Casting Factor 1.0 M. Kullick...... 2681

Ti-Applications in High Pressure and High Temperature Ducts C. Sefrin, W Beck...... 2689

Development of Low Cost Near Net Shape Forgings from Ti 6-4 by Special Process Technology T Witulski, G. Terlinde, G. Fischer...... 2697 Contents XXXIX

Titanium Investment Castings for Airbus Nicolai, C. Liesner...... 2705

Take-Off on Titanium W Horvath, W Marketz, E. Gach...... 2713

A Study of Oxygen Diffusion Zones in Ti3Al2.5V Tubes and Ti6A14V Sheets and Introduction of a Detection Method U. Pilchowski...... 2719

Volume V

Aero-Propulsion Applications

Keynote Paper The Current Status of Titanium Alloy Use in Aero-Engines D. Rugg...... 2727

Titanium Industry Quality Improvements C. Shamblen, A. Woodfield, P Wayte, G. Dibert...... 2737

Residual Stresses in Linear Friction Welded IM1550 M. Preuss, J. Quinta da Fonseca, A. Steuwer, L. Wang, P J. Withers, S. Bray...... 2745

High Frequency Inductive Press Welding of (a+β) Titanium Alloys S. Lütjering, 0. Roder D. Helm...... 2753

Effects of FOD on Fatigue Crack Initiation of Ballistically Impacted Ti-6A1-4V Simulated Engine Blades J. C. Birkbeck, D. Eylon, T Nicholas, S. R. Thompson...... 2761

Evaluating Fretting Fatigue Life of Titanium Alloy Dovetails by Using Stress Singularity Parameters T Yoshimura, H. Fukunaga, H. Tao, T Hattori...... 2769

Technological Aspects of Intense Pulsed Electron Beam Application for Properties Improvement and Repair of Gas Turbine Engine Blades from Titanium Alloys N. A. Nochovnaya, V Shulov, A. Paykin, V Engelko, G. Mueller A. Weisenburger...... 2777 XL Contents

Basics on Laser Cladding of Ti 6246 for the Repair of Damaged Compressor Blades for Jet Engines S. Keutgen, G. Backes, I Kelbassa, E. W Kreutz...... 2785

Residual Stress Evolution during Heat Treatment and Machining of Forged Ti- 6Al-4V Turbine Engine Parts — Computational Simulation in Comparison to Experimental Investigations W Marketz, P Staron, U Cihak, H. Leitner, H. Clemens...... 2793

Residual Stresses in Unfatigued and Fatigued Laser Shock Peened Fan Blade Roots A. King, A. D. Evans, M. Preuss, P J. Withers, C. Woodward...... 2801

Mechanical Properties and Microstructure of Ti40 Bum Resistant Alloy Ring H. Wu, Y Q. Zhao, C. L. Liu, Y. L. Li, K. Y Zhu...... 2809

The Surface Integrity of a Burn Resistant Titanium Alloy (Ti-25V-15Cr-2Al-0.2C wt%) after High Speed Milling and Creep Feed Grinding D. Novovic, D. K. Aspinwall, R. C. Dewes, W. Voice, P. Bowen...... 2817

Study on Microstructure of Ti40 Burn Resistant Titanium Alloy As-Cast C. L. Liu, Y Q. Zhao, H. L. Qu, K. Y. Zhu, H. Wu, Y L. Li...... 2825

Micromechanisms of Fracture in Burn Resistant Ti-25V-15Cr-2Al-0.2C Alloy T Udomphol, M. Wenman, W Voice, P Bowen...... 2829

Applications of Quantitative Fractography to Titanium Alloys M. Bowry, D. Rugg, P Bowen...... 2837

Special Papers: Aero-Engines

Titanium in Aero-Engines J. Eßlinger, D. Helm...... 2845

Microstructure and Mechanical Properties of Screw-Press Forged Titanium Jet Engine Discs W Horvath, J. Tockner, R. Münzer...... 2853

Precision Forging of Titanium Compressor Blades F. vom Wege...... 2859

Friction Welding of Aero Engine Components S. W Kallee, E. D. Nicholas, M. J. Russell...... 2867 Contents XLI

Microstructure and Mechanical Properties of Inertia and Electron Beam Welded Ti-6246 0. Roder, D. Helm, G. Lütjering...... 2875

The Influence of Manufacturing Anomalies on Fatigue Performance of Critical Rotating Parts in the Aero-Engine W D. Feist, F. Niklasson, K. M. Fox...... 2883

Development of Ti-6-2-4-6 Engine Discs G. Terlinde, T Witulski, G. Fischer...... 2891

TiAl — New Opportunity in the Aerospace Industry D. Roth-Fagaraseanu, F. Appel...... 2899

Titanium Matrix Composites for Demanding Structural Aerospace Applications C. Leyens, J. Hausmann, J. Hemptenmacher...... 2907

Burn Resistant Titanium Alloy (BuRTi) W E. Voice...... 2915

Marine, Offshore, Power Generation

Keynote Paper Application of "I itanium to Ocean Civil Engineering and Marine Vessels in Japan K. Kinoshita, T Oda...... 2923

Titanium Alloy Utilization in Drilling and Offshore Production Systems R. W Schutz, C F. Baxter, P L. Boster...... 2935

Design, Manufacture, and Assembly of Ti-6Al-4V ELI Tapered Stress Joints V Venkatesh, J. Grauman, J. DiPasquale, J. Barber...... 2943

Sustained Load Cracking Resistance of Forged Grade 29 Titanium Riser Components J. D. Burk, R. W. Schutz, R. L. Porter...... 2951

Fatigue Strength of CP Grade 2 Titanium Fillet Welded Joint for Ship Structure T Iwata, K. Matsuoka...... 2959 XLII Contents

Optimizing the Design of the Deep-Water Power Generating Unit Casing Made of Titanium Alloys Y. A Maximov, V V Travin, L. V Lysenko...... 2967

Application of TIMET Alloys for High Speed Motor Rotor A. I. Balitskii, S. J. S. Ford, G. Mascalzi, V I. Pokhmurskii, R. Thomas...... 2975

Production of All Titanium Brazed Heat Exchanger K. Matsu, Y. Miyazawa, T Onzawa, T Ariga...... 2983

Structural — Phase Transformation in Metal of Blades of Steam Turbines from Alloy VT6 after Technological Treatment M. A. Skotnikova, Y. M. Zubarev, T A. Chizhik, I. N. Tsybulina, T L Strokina...... 2991

Emerging Markets

Keynote Paper

Emerging Applications for TitaniumF. H. Froes, K. Yu...... 2999

Mass Production of Gamma TiAl- Automobile- Valves on Prototype Scale M. Blum, H. Franz, G. Jarczyk, P Seserko, H. J. Laudenberg, K. Segtrop, P Busse...... 3011

Heat Resistant Titanium Alloy for Mufflers, Ti-1.5%Al N. Matsukura, T Yashiki, A. Okamoto, Y Miyamoto, Y. Yamamoto...... 3019

Development of Low Cost High Strength Alpha/Beta Alloy with Superior Machinability Y Kosaka J. C. Fanning, S. P Fox...... 3027

Processing and Properties of Ti-38-644 Alloy for Titanium Automotive Suspension Springs V R. Jablokov, J. R. Wood, B. G. Drummond...... 3035

Influence of Heat Treatment and Shot Peening on Fatigue Behavior of Suspension Springs Made of TIMETAL LCB J. Kiese, W Walz, B. Skrotzki...... 3043

Development of a Titanium Connecting Rod for Automotive Quantity Production M. Scholz, J. Wronski, K. Bennewitz, S. Eisenberg, K. Faller, R. Thomas...... 3051 Contents XLIII

Influence of Alloy Composition and Heat Treatment on the Fatigue Behaviour of Titanium Connecting Rods K. Bennewitz, M. Scholz, S. Eisenberg, K. Faller, R. Thomas...... 3059

Investment Casting of Automotive Turbocharger Rotor Using TiAl Alloy M.-G. Kim, S.-Y. Sung, W Ha, Y-I. Bae, S. K Kim, S.-H. Lee, Y-J. Kim...... 3067

Development of Titanium Alloy Engine Valves for Motorcycles T Tominaga, T Suzuki, H. Takeuchi, H. Fujii, K. Kinoshita, M. Ishii, Y Yamashita ...... 3075

Research on Low Cost Titanium Alloy Y Q. Zhao, Y L. Li, H. Wu, C. L. Liu, L. Feng, K. Y Zhu...... 3083

New Alpha-Beta Titanium Alloy, KS Ti-4.5Al-4Cr-0.5Fe-0.2C, Possessing Both Extremely Low Flow Stress during Hot Working Similar to Grade 2 and High Strength Comparable to Grade 5 S. Kojima, H. Oyama...... 3089

New Coilable High-Strength Alpha-Beta Titanium Alloy, KS Ti-9, with Properties Comparable to Ti-6Al-4V S. Kojima, H. Oyama...... 3097

Development of New High Performance Titanium for Buildings T Yashiki, Y Miyamoto, Y Yamamoto, A. Okamoto, E. Yoshikawa, K. Yanagisawa...... 3103

A Cleaning Method for Aged Architectural Titanium A. Pelayo, P Cano, M. Vaquero...... 3111

Surface Morphology and Discoloration Behavior of Titanium Sheets Pickled in Nitric-Hydrofluoric Acid Solutions K. Takahashi, M. Kaneko, T Hayashi, J. Tamenari, H Shimizu...... 3117

Ballistic Evaluation of Ti-6Al-4V Plate for Protection Against Small Arms Projectiles J. C. Fanning...... 3125

Development of a New Beta Titanium Alloy Ti-15V-6Cr-4Al for Golf Club Heads A. Suzuki, T Noda, M Okabe...... 3133

The Application of Ti-20V-4Al-1Sn Alloy to Golf Club Head S. Matsumoto, N. Ariyasu, K. Nagashima...... 3141 XLIV Contents

Manufacturing, Quality Control and Assessment of the Cryogenic Properties of α Titanium Alloy for Application to the Coil Suspension System of the Compact Muon Solenoid (CMS) S. Sgobba, B. Levesy, S. Sequeira Tavares...... 3149

Porous Titanium with Reticulate Structure for Orthopaedic Implant J. P Li, K. de Groot...... 3157

Development of New High Strength Beta Ti Alloys for Biomedical Applications F. Guillemot, F. Prima, R. Bareille, D. Gordin, T Gloriant, D. Ansel, C. Baquey, M. C. Porté-Durrieu...... 3165

Mechanical Properties of New Ti-Fe-Ta and Ti-Fe-Ta-Zr System Alloys D. Kuroda, H. Kawasaki, S. Hiromoto, T Hanawa, S. Kuroda, M. Kobayashi...... 3173

Mechanical Performance and Biocompatibility of Low Rigidity Titanium Alloys, Ti- 29Nb-13Ta-4.6Zr, for Biomedical Applications T Akahori, M Niinomi, H. Fukui, A. Suzuki, Y Hattori, S. Niwa...... 3181

Young's Modulus and Mechanical Properties of Ti-29Nb-13Ta-4.6Zr for Biomedical Applications Y L. Hao, M. Niinomi, D. Kuroda, Y L. Zhou, R. Yang, A. Suzuki...... 3189

Evaluation of Mechanical Properties of ASTM Gr.2 Commercially Pure Titanium and Ti-6Al-4V ELI in Liquid Hydrogen H. Fujii, H. Kimura, J. Tanaka...... 3197

Effect of Plastic Deformation and Static Stress on Corrosion of Ti-6Al-4V Alloy Y Goto, I Komotori...... 3205

The Application of the Bi-Lamellar Heat Treatment to Titanium Orthopedic Implants H.-P Nicolai, C. Liesner, J. Albrecht, G. Lütjering...... 3213

Evaluation of Corrosion Resistance and Biocompatibility of Ti-Ni Alloy Y Kimura, T Honma, M. Morita...... 3221

Corrosion Resistance of Titanium and Titanium-Silver Alloys in the Fluoride-Containing Artificial Saliva H.-M. Shim, K.-T. Oh, K.-N. Kim...... 3229 Contents XLV

Cyclic Deformation Behavior of Ti-6Al-4V and Ti-6A1-7Nb in Different Quasi-Physiological Media B. Schwilling, C. Fleck, F. Walther, D. Eifler...... 3237

A Comparative Study of Wear Properties of Ti-Nb-Ta-Zr Alloys and Ti-6Al-4V S. J. Li, R. Yang, S. Li, Y. L. Hao, Y. Y. Cui, M Niinomi...... 3245

Finite Element Modelling of Proximal Humeral Fractures Reinforced by Intramedullary Titanium Nailing J. Fierlbeck, B. Füchtmeier, J. Hammer M. Nerlich...... 3253

Dental Casting of Ti-Cr-Cu Alloys M. Koike, L. Gun, L. Carrasco, M. Brezner, Z. Cai, M. Ito, 0. Okuno, T Okabe...... 3261

Surface Reaction Layer and Mechanical Performance of Low Rigidity Titanium Alloy, Ti-29Nb-13Ta-4.6Zr, Cast by Dental Precision Casting Method M. Niinomi, T Akahori, T Manabe, T Takeuchi, S. Katsura, H. Fukui, A. Suzuki...... 3269

Interactions between Cells and Metal Oxide Surfaces E. Eisenbarth, D. Velten, M. Muller, N. Schanne, S. Keceli, H. Hildebrand, C. Schmitt, R. Thull, J. Breme...... 3277

Characterization of Electrochemical Interface between Titanium and Cells S. Hiromoto, F. Mizuno, Ti Hanawa, K. Asami...... 3285

Effect of Pre-Oxidation on Formation of Apatite Coatings on Titanium SurfaceF. Liang, Z. Yu, K. Wang, L. Zhou...... 3293

Electrodeposition of Hydroxyapatite on Titanium for Implants N. Eliaz, T M. Sridhar, Y. Rosenberg...... 3299

Corrosion Behavior of the Material Combination Titanium — Plasma Sprayed Titanium Coating — Bone Cement in Artificial Bone Fluid R. Lerf, L. Reclaru, P Y. Eschler, A. Blatter...... 3307

Improvement of the Surface Structure and of Functional Coatings on Titanium Alloys in Contact with Blood S. Winter, F Aubertin, U. T Seyfert, M. Moller, R. Thull, J. Breme...... 3315

Biocompatibility of Calcium Phosphate Film Made by Electrochemical Method K. Suzuki, F Kimura, M. Morita...... 3323 XLVI Contents

RGD Peptide Grafting onto Ti-6Al-4V: Physical Characterization and Interest towards Human Osteoprogenitor Cells Adhesion M. C. Porté-Durrieu, F. Guillemot, S. Pallu, C. Labrugère, B. Brouillaud, R. Bareille, N. Barthe, C. Baquey...... 3331

Spark Anodization on Titanium and Titanium Alloys P Becker, A. Baumann, F. Lüthen, I Rychly, A. Kirbs, U Beck, H.-G. Neumann...... 3339

Atmospheric Plasma Spraying (APS) of Graded Multilayer Titanium Dioxide/ Calciumphosphate Coatings on Titanium for Biomedical Implants M. Baccalaro, R. Gadow, C. C. Stahr, K. von Niessen...... 3345 Ti³ + Surface Defects Generation by UHV Low-Temperature AnnealingF. Guillemot, C. Labrugère, C. Baquey, M C. Portè-Durrieu...... 3353

Biocompatibility of Ti-6Al-4V Alloy Modified by Fine Particle Bombardment (FPB) K. Murai, J. Komotori, Y Kameyama, T Yamada, E. Shimodaira...... 3361

Improvement of ß Titanium Alloys Surface Properties by Vacuum Laser Treatment F. Guillemot, F. Prima, S. Lazare, S. Gamier, M. C. Porté-Durrieu, V Takarev, C. Belin, D. Ansel, C. Baquey...... 3369

Influence of Laser Marking on the Fatigue Behavior of Ti-6Al-7Nb Alloy M. Windier, R. Steger...... 3377

Shape Memory Characteristics of Ti-Base Biomedical Shape Memory Alloys H. Hosoda, Y Fukui, T Inamura, K Wakashima, S. Miyazaki...... 3385

Special Papers: Automotive Applications

Titanium in Automotive Applications — Nightmare, Vision or Reality H. Friedrich, J. Kiese, H.-G. Haldenwanger, A. Stich...... 3393

Optimization of Deep Drawing Processes for the Low-Cost Manufacturing of Automotive Titanium Exhausts 0. Schauerte, M. Kramer, J. Kiese, W Walz...... 3403 Contents XLVII

Titanium Aluminides for Automotive Applications H. Baur, D. B. Wortberg...... 3411

Low-Cost Production Lines for Emerging Applications Like Automotive H. Sibum...... 3419

Author Index...... At the end of each volume

Subject Index...... At the end of each volume Precision Forging of Titanium Compressor Blades

F. vom Wege ThyssenKrupp Turbinenkomponenten GmbH, Remscheid, Germany

Abstract

The combination of high strength-to-weight ratio, excellent mechanical properties, fatigue behaviour and creep resistance made titanium alloys to requested materials for static and rotating engine parts like compressor blades. Forging of titanium alloys improves the mechanical properties of compressor blades due to the optimized grain flow. Simultaneously the amount of necessary raw material can be significantly reduced by precision and near net shape forging. This paper explains the forging technology, thermomechanical treatment and resulting microstructure of various titanium alloys like Ti64 as well as Ti6242 and Ti834 for elevated temperature applications. Beside microstructures achievable geometrical tolerances are discussed. For future applications ThyssenKrupp's possibilities to isothermal forge TiAl blades with high specific strength and high temperature resistance will be illustrated.

1 Introduction

Due to their low density and high specific strength titanium alloys are used for forged blades in the low and high pressure part of compressors for aero-engines. Applied alloys are Ti 6-4, Ti 6-2-4-2, Ti 6-2-4-6, Ti 8-1-1, Ti 685, Ti 679, Ti 829 and Ti834. Operating temperatures of 550°C can be realized with Ti 6-2-4-2 and Ti 829, up to 600°C with Ti 834 [1]. For higher operating temperatures competing with those of nickel based superalloys γ-TiAl production and forging routes are in development [2,3]. The presented paper illustrates the production route for precision forged compressor blades for the most common titanium alloys. The focus is set on forging technology, microstructure and dimensions.

2 Forging Technique

The forging technique of compressor blades for aero-engines is defined by the geometry, the required microstructure and the allowed dimensional tolerances. It has to be distinguished between single ended rotor blades and double ended stators (Fig. 1). 2860

Figure 1: a) HP Rotor 1, Trent 800 b) IGV Stator Trent 700

This final geometry defines the mass distribution and the applied forging route. A typical forging sequence for a rotor blade of Ti 6-4 is shown in Fig. 2.

Figure 2: Example for a typical forging sequence of a titanium rotor blade

It consists of extruding the airfoil section from bar stock, heading the root portion, preforging of the final shape and final forging. Each forging step is conducted in an individual heat. The forging operations on the preforms are conducted on crank presses whereas final forging is performed on screw presses of 630-2300 t nominal force. The screw presses are frequency controlled. This allows to define the forging energy to apply a precise thermomechanical treatment on the forgings. Materials with less forgeability can be deformed economically with homogeneous microstructures without detrimental effects of friction and shearing. To reduce oxidation of the workpiece and friction in the die the parts are glass coated before forging. The forging temperature is defined by the requested microstructure. For Ti 6-4, Ti 6-2-4-2 or Ti 834 normally a bimodal α+β microstructure is ordered by the customer, partially with restricted α-content. This means that the parts are forged with a temperature distinctively below beta transus. Typical forging temperatures for various alloys are shown in Table 1. The final α-content is generated by a seperate solution heat treatment about 15-30°C below the beta transus temperature. For each furnace run (= heat treatment batch) the microstructure, especially the α-content is checked and the solution heat temperature adjusted if necessary. The electrical heat treatment furnaces are permanently checked and have tight tolerances of ±5 °C from the set point to realize the requested microstructures. For β-microstructures the forging temperature is in the range of the beta transus temperature. As the microstructure consists only of one phase care has to be taken to avoid coarse grain or uncontrolled grain growth. Similar to the α+β microstructures the final β-microstructure is generated by a subsequent solution heat treatment. Typical examples for α+β and β-microstructures are shown in Fig. 3. 2861

Figure 3: Microstructure of different titanium alloys 2862

To improve fatigue strength the primary α-content of α+β microstructures is restricted to a small range. The advantages of the forging route are the grain flow which allows higher stresses and saving of material. Nowadays compressor blades can be precision forged with geometrical tolerances for the gas flow area which requires no subsequent machining of the airfoil except special surface treatments to achieve ultrafine surface roughnesses of Ra = 0,4μm or peening to increase the fatigue strength. Typical geometrical tolerances of precision forged blades are demonstrated in Fig. 4.

Figure 4: Geometrical tolerances of precision forged compressor blades

Convex and concave side of the airfoil as well as platforms at the root and shroud end, that means 4 planes are precision forged simultaneously with very tight tolerances. This technology is known as four phase annulus forging. Beside the shape (profile) twist and bow of the airfoil are restricted as well. Normally leading and trailing edge of precision forged compressor blades are machined in one of the first operations after forging. Actually ThyssenKrupp controls the chord width by a precision forging operation so that no subsequent machining operation is necessary. Dimensionally leading and trailing edge are ready for assembly. A new development in compressor blade forging technology is near net shape forging of root and shroud area. Instead of a simple square block for the endings in the past, the shape of the near net shape forging is more and more adjusted to the final shape of the finished machined compressor blade (Fig. 5). 2863

Figure 5: Precision forged titanium blade with near net shape root

Precision forgings with economy root need less raw material. Additionally the first grinding operation of the root area can be omitted, which saves machining time, tooling costs and handling costs for encapsulation. The capability of this advanced forging technology lead to the application of near net shape forging to impellers. A comparison of the finished machined part and the near net shape forging is shown in Fig. 6.

Figure 6: Comparison of a finished machined an a final forged impeller of Ti 64

The saving in material combined with the positive effect of grain flow can be easily concluded. The actual diameter of this impeller is about 90 mm, the maximum diameter 200mm restricted by the size of the applied screw press with 2300 t nominal force. Using larger presses up to 8000 t, which are available at ThyssenKrupp, this technology can be applied to larger impellers too. This technology might be an interesting alternative to milling from a solid bar. A new group of titanium material approaching to practical applications is γ-TiAl. Together with other institutional and industrial partners ThyssenKrupp Turbinenkomponenten developed an isothermal forging route for high pressure γ-TiAl rotor blades [1,2]. Fig. 7 shows such a blade in the forged condition. 2864

Figure7: Isothermal forged TiAl blade in the as forged unclipped condition

The forging will be machined to final dimensions subsequently. γ-TiAl forgings are significantly lighter than commonly used nickel based forgings and even lighter than titanium alloys. Compared to TiAl castings TiAl forgings allow a higher damage tolerance and fatigue strength. Actually Thyssen evaluates the conditions for serial production of γ-TiAl compressor blades. One step is the application of a multiple forging, which allows the production of several forgings in one forging step (Fig. 8).

Figure 8: Multiple forging of TiAl blades in the unclipped condition

Details of these forged TiAl-compressor blades are presented in another paper on this conference

3 Conclusion

It was demonstrated that all common and advanced titanium alloys like γ-TiAl can be precision forged to compressor blades. The applied forging route is defined by the forgeability of the material and the geometry of the compressor blade. Beside precision forging of the airfoil actual forging technology is focused on near net shape forging of the inner and outer fixing of a compressor blade, which means material saving and a distinctive reduction of subsequent maching costs. Long term experience in precision forging of compressor blades lead to tighter geometrical tolerances and complex shapes. Latest example for this advanced forging technique are near net shape forged impellers with twisted airfoils which means a new challenge of forging technology. 2865

4 References

1. G. Proske, G. Terlinde, G. Fischer, Influence of Thermomechanical Processing on Mechanical Properties of Ti-1100 Compressor Disks, Proc. 8th World Conf. On Titanium, P. A. Blenkinsop, W.J. Evans, H.M. Flower eds. Birmingham 1995 2. F. Appel, U. Brossmann, U. Christoph, St. Eggert, P. Janschek, J. Müllauer, M. Oehring, D.H. Paul, Recent Progress in the Development of Gamma Titanium Aluminide Alloys, Advanced Engineering Materials 2000, 2 , No. 11 3. P. Janschek, Entwicklung einer Schmiedetechnologie zur Herstellung von Verdichter- schaufeln aus γ-TiAl, Schmiede-Journal, Sept. 1999 Friction Welding of Aero Engine Components

S. W. Kallee, E. D. Nicholas, M. J. Russell TWI Ltd, Cambridge, UK

Abstract

New methods of friction welding are becoming more widely implemented in the manufacture of aero engines, because these solid phase joining processes provide high weld quality and economic benefits. After the world-wide acceptance of rotary friction welding (Fig. 1), the aero engine industry is now implementing linear friction welding, and is considering friction stir welding, friction taper stitch welding and friction surfacing. Friction welding processes are substantially automated, and reproducibility is high in comparison to manual welding processes. Friction welding processes are generally tolerant to wide changes in the welding parameters without compromising quality, thus reliability is high. In particular one process, linear friction welding, can be used to join a variety of complex profiles. It is technically, commercially and environmentally a very attractive process. It has been demonstrated for virtually all types of engineering alloys, and novel solutions have been devised to reduce the manufacturing cost of the equipment, mainly based on using hydraulic actuation and stored energy concepts. This will lead to a very substantial reduction in equipment price.

1 Introduction

High-strength titanium alloys are of interest for structures requiring minimum weight, especially in the aerospace industry. Along with the interest in high-strength alloys, there is a growing requirement to join titanium alloy components. For high-performance applications an improved strength/toughness combination is needed, and for this reason the solid phase friction welding processes have been developed, as they are likely to have a good balance of properties in titanium alloys. Friction welding processes also permit the joining of dissimilar titanium alloys, thus making best use of specific alloy properties at the operating location.

2 Rotary Friction Welding

Titanium alloys in general respond very well to rotary friction welding, and the process is widely used in the aerospace industry for joining many engine components [1]. Frictional heat is developed by rotating one axially symmetrical component against another stationary component under an applied force. Frictional heating causes the materials to soften at the interface, and after a short time the interface is sufficiently hot to allow the rotation to be stopped. A higher forging force is then usually applied to consolidate the joint. Rotary friction welding is very energy efficient compared to most competitive welding processes, and no consumables such as filler 2868 wire, flux or shielding gas are required, even for environmentally sensitive materials such as titanium alloys. Rotary friction welding can be divided into two distinct variants. In the continuous drive variant, the rotating component is constantly driven by an electric or hydraulic motor, which can be braked as the forge force is applied. An alternative is inertia friction welding, where the rotating component is attached to a flywheel (making use of stored energy), and the non-rotating consumable is used as a brake, thus converting the kinetic energy of the flywheel to heat at the interface. Continuous drive friction welding is more common in Europe, and inertia friction welding is more common in the USA. A feature of inertia friction welding, which can sometimes be an advantage, is that the rate of energy transfer is high at the start of the weld. Although there may be subtle metallurgical differences in the welds made by the two processes, the end results are very similar, and either process can be used to make high-quality welds.

Figure 1. Rotary friction welding of a Ti-6A1-4V pipe (ø250mm, 17mm wall thickness)

Both Ti-6A1-4V (Fig. 1) and Ti-10V-2Fe-3A1 alloys (Fig. 2) can be successfully joined using rotary friction welding [1,2,3]. The joints produced exhibit tensile strength and impact toughness values comparable to the parent metal. Whilst post weld heat treatment may be advisable for the Ti-6A1-4V to stress relieve the joints, there is little measurable benefit to the tensile and impact toughness. However, post weld heat treatment is vital to the Ti-10V-2Fe-3A1 to obtain the best balance of properties. It has been reported that friction welds exhibit a superior combination of strength and toughness in comparison fusion welds. Rotary friction welding shows also great potential for joining titanium aluminide intermetallic compounds.

Figure 2. Rotary friction weld and a macrograph of a Ti-10V-2Fe-3A1 alloy cylinder (ø60mm, 20mm WT) 2869

3 Linear Friction Welding

3.1 State of the Art of Linear Friction Welding Linear friction welding (LFW, Fig. 3) has been demonstrated for virtually all types of engineering alloys, such as titanium (Fig. 4), nickel based alloys, aluminium, steel, stainless steel and intermetallics. The process can be used to join a variety of complex profiles, giving good functionality. It is technically, commercially and environmentally a very attractive process. It is ideally suited to both mass production and to the manufacture of specialised components required in limited numbers. If different components are produced, only the tooling to hold the work pieces needs to be changed and different welding parameters may need to be set.

Figure 3. Principle of linear friction welding Figure 4. Linear friction welded titanium blocks In the early 1980s the first concepts were developed to use linear reciprocating motion for non-round parts. A major break-through was made by reducing the amplitude at the end of the weld cycle instead of slowing down the frequency to terminate the friction phase. As a consequence, the workpieces were accurately aligned with respect to each other. In 1990 the first dedicated linear friction welding machine for welding metals was commissioned at TWI (Fig. 5 & 6).

Figure 5. TWI's electro-mechanically actuated linear Figure 6. Mechanism to develop linear friction welding machine reciprocating motion with variable amplitude in TWI's electro-mechanical LFW machine When using this electro-mechanical linear friction welding machine, it was demonstrated that excellent weld quality could be achieved by this process. This helped companies such as Rolls Royce, MTU Aero Engines (Fig. 7) and Pratt & Whitney to introduce linear friction welding into their commercial production. 2870

Figure 7. Electro-mechanical linear friction welding machine built by Blacks Equipment and used by MTU Aero Engines Munich in the series production of aero engine blisks [4,5]

One area for potential application of linear friction welding machines is the manufacture or repair of blisks (blades on disks) of aero engines and stationary turbines. Linear friction welding could be used by producers of stationary turbines as well as by producers of aero-engines. It seems to be the ideal process for joining blades to disks (Fig. 8), as the melting point of the workpieces is not reached during the operation.

Figure 8. Joining of blades to disks by linear friction welding to produce blisks

The uptake of linear friction welding by industry may have been impaired by the high capital cost of existing mechanical linear friction welding machines. Novel solutions have been devised to reduce the cost of the equipment, mainly based around the use of more efficient power sources and stored energy concepts. Several studies [6] were conducted consisting of a historic review, the selection of the most suitable actuation system, a market analysis [7] and some preliminary welding trials (Fig. 9).

Figure 9. Metallographic section through a linear friction weld of Ti-6A1-4V 2871

3.2 The LINFRIC® Project on Developing Hydraulically Actuated LFW Machines The LinFric® project was conducted to drastically reduce the cost of linear friction welding equipment, in order to make the technology more accessible to potential users especially from the power generation, automotive and aerospace industrial sectors. This international project, which was partly funded by the European Community, was conducted by 8 organisations. It started on 1 October 1998 and had a duration of 36 months. The consortium consisted of five small and medium sized enterprises (SMEs) from three countries, supported by one larger company, and two research and development organisations [8,9,10,11].

3.3 The LINFRIC® Machine Specification A full-size prototype LinFric® machine was designed, built and commissioned by the project participants. The machine consists of a machine base on which a traverse carriage is mounted via reciprocating ball bearings. Hydrostatic bearings are used to re-act the welding and forging forces. A hydraulic actuator which is fixed in a vertical actuator mounting frame generates the linear reciprocating motion (Fig. 10). A manual guard covers the machine to fulfil health and safety requirements (Fig. 11).

Figure 10. Artist Impression of the LinFric® machine Figure 11. Fully assembled prototype LinFric® machine being tested with manual guards at TWI

The machine base and the axial loading system are based on existing typical designs of rotary friction welding machines. The design of the prototype LinFric® machine is similar to that of fixed head rotary friction welding machines, where the rotating component is not moved in the axial direction, but the non-rotating component is clamped onto a traversing carriage and then pushed against the rotating component. Linear bearings with reciprocating balls are used to guide the traversing slide. One hydraulic actuator is positioned behind the workpiece in the centreline of the components. A backstop is placed behind the clamp to transfer the forces generated by the traverse cylinder. It transfers the forces into a traverse cylinder bracket. The machine concept includes the use of a hydraulic actuator similar to those being used in commercial fatigue testing machines (Fig. 12). The machine is not balanced and therefore the machine base might vibrate, as the centre of gravity will be kept stationary. Thus an up-and-down motion of the oscillating carriage (Fig. 13) is preferred against a movement in the horizontal direction. The machine is fixed onto energy mounts to avoid vibrations being transferred into the workshop floor. To reduce the vertical movement of the machine base, compensating weights artificially increase the mass and inertia of the machine base. Therefore the total weight, excluding the hydraulic power pack, is approximately 12t. 2872

Figure 12. The prototype LinFric® machine, suitable for welding Figure 13. The automated light-weight cross sections of up to 2000mm2 at frequencies of up to 125Hz tooling of the prototype LinFric® machine amplitudes of up to ±3mm

The oscillating carriage is mounted onto the hydrostatic bearing bracket using hydrostatic bearings. The following parameters were used for dimensioning the parts (Table 1):

Table 1. Basic parameters for the LinFric® machine design

4 Friction Stir Welding

Friction stir welding is a solid phase process and lends itself to unique joint configurations. It was invented and patented by TWI in 1991. Originally, it was seen as the joining solution for aluminium sheets, but the list of suitable materials for friction stir welding grows monthly. As the tool designs are being refined, even the higher melting point materials like steel, stainless steel and titanium [12] are finding their way onto the suitable materials list. The EUREKA EuroStir® project has been devised to establish more industrial applications of the process in Europe [13] . 2873

5 Other Friction Welding Processes

The Friction and Forge Welding Group of TWI conducts research and development on further friction based welding processes such as friction taper stitch welding, friction surfacing and its variant friction seam welding. These are now being considered for repairing blades of aero engines. A versatile prototype machine was built in the CEMWAM project and has now been installed in TWI's laboratory for conducting feasibility and parameter optimisation studies. One part of the CEMWAM project had the requirement to further develop friction welding, for alternative joint geometries of aero engine components. Within this work, the concepts of using friction taper stitch welding and friction seam welding were proven for an aerospace alloy. A machine design was developed to have one machine able to weld with both process variants, which has the advantage of flexibility for the manufacturer and for future application developments. The welding trials undertaken in parallel with the machine build, proved that friction stitch welds could be made through previously brazed joints. This gives future advantages for certain aero engine parts and alloys, of enhancing the strength and performance of brazed joints and of reducing the jigging requirements for the joint which can give significant savings in manufacturing costs and lead time. It is also being considered to use this machine for attaching bosses to engine casings by friction stud welding to eliminate the need for forging and machining and thus reducing manufacturing cost.

6 Acknowledgements

The LinFric® project 'Development of a Low Cost Linear Friction Welding Machine' was jointly funded by the industrial consortium and the Commission of the European Communities under their CRAFT Initiative (Co-operative Research Action for Technology). The total budget 1 was 1,236,000 Euro and involved an effort of more than 7 /2 man years. The authors want to thank all LinFric® participants for their technical contributions and valuable discussions during this project. All participants are very thankful for the financial support provided by the European Commission and for the excellent scientific supervision.

7 Conclusions

The following conclusions can be drawn: • Solid phase friction welding processes are used to produce high-quality joints in titanium alloys. • Rotary and linear friction welding have been implemented by several aero engine manufacturers. • A prototype hydraulic linear friction welding machine has been assembled, commissioned, tested and demonstrated in a collaborative project, and a strategy for producing and selling these LinFric® machines has been developed. • Research and development projects are being conducted on applying other friction welding processes to titanium alloys, e.g. friction stir welding, taper stitch welding and friction stud welding. 2874

8 References

1. P L Threadgill: "The potential for solid state welding of titanium pipe in offshore industries", Conf on right use of titanium III, Stavanger, Norway, 4-5 Nov 1997. 2. L S Smith, P L Threadgill and M Gittos: "Guide to best practice — welding titanium". Edited by D Peacock, Titanium Information Group, May 1999. 3. A Wisbey, I C Wallis, H S Ubhi, P D Sketchley, C M Ward-Close and P L Threadgill: "Mechanical properties of friction welds in high strength titanium alloys." 9th World Titanium Conference 'Titanium '99', St. Petersburg, Russia, June 1999. 4. http://www.frictionwelding.com/mach6.htm 5. http://www.users.globalnet.co.uk/~blacks/linear_welding.html 6. R A Black and P L Threadgill: "Low cost linear friction welding; A feasibility study". Phase 1 CRAFT project document, contract BRST-CT96-0242, June 1997. 7. M Skinner: "Advanced engineering solutions - aerospace engine manufacturers". http: //www.mts.com/aesd/AdvanMan.htm and http://www.mts.com/aesd/aerospace_engine.htm 8. E Raiser, R A Black and S W Kallee: "LinFric®" http://www.linfric.com 9. E Raiser and S W Kallee: "LinFric® - Entwicklung einer hydraulischen Linearreib- schweißmaschine". International Exchange of Experience at SLV Munich, 5 March 2002. 10. S W Kallee: "A CRAFTy way to join the welding business". Materials World, Jan 2001. 11. S W Kallee and Y Ghanimi: "Entwicklung von kostengünstigen Linearreibschweißma- schinen". Schweiß- & Prüftechnik 02/2001. 12. M J Russell: "Friction stir welding of titanium alloys — a progress update." 10th World Conference on Titanium, 13-18 July 2003, Hamburg, Germany. 13. http://www.eurostir.co.uk Microstructure and Mechanical Properties of Inertia and Electron Beam Welded Ti-6246

O. Roder1, D. Helm1, G. Lütjering2 1MTU Aero Engines GmbH, Munich, Germany 2Technical University Hamburg-Harburg, Hamburg, Germany

Abstract

The high strength near β-titanium alloy Ti-6A1-2Sn-4Zr-6Mo (Ti-6246) in the β-forged condition offers higher strength levels combined with a higher toughness as compared to Ti-6A1-4V or Ti- 6Al-2Sn-4Zr-2Mo. This combination makes β-forged Ti-6246 particularly suitable for compressor disks and BLISKs (bladed disks). In this application area, inertia and electron beam welding are common practices to join axially symmetrical parts. The goal of the present work was to investigate the microstructural changes of Ti-6246 due to welding and the response to post weld heat treatments. Specimens of β-processed and fully heat treated Ti-6246 material (910°C/ 1 h + 595°C/ 8h) were joined by inertia friction and by electron beam welding. The microstructure in the welded zone was investigated by optical microscopy and transmission electron microscopy. In addition to the as- welded condition, the effects of two post-weld heat treatments were investigated (595°C/ 2h and 640°C/ 2h). Besides microstructural investigations tensile, creep, and load controlled low cycle fatigue tests were performed. The results of the mechanical tests will be described in terms of the microstructural changes observed in the welded zone.

1 Introduction

Ti-6Al-2Sn-4Zr-6Mo (Ti-6246) is a heat treatable high strength titanium alloy originally developed in the 1960s to combine the long term, elevated temperature strength properties of Ti-6A1-2Sn-4Zr- 2Mo-0,08Si (Ti-6242S) with a much improved short term strength [1]. According to more recent investigations this alloy can be designated as a near β-titanium alloy, mainly due to the observation that even quenching from the one-phase β-field doesn't lead to a martensitic transformation within the material [2]. The alloy Ti-6246 has gained some recent interest in the β-forged condition for applications in the compressor section of aero engines up to 450°C, replacing conventionally used alloys like Ti-6Al-4V or Ti-6242S. Compared to these two alloys β-forged Ti-6246 offers higher strength levels combined with a higher toughness. This combination makes it particularly suitable for compressor disks and BLISKs (bladed disks) in aero engines. Titanium alloys offer a good weldability as long as the process is performed under absence of oxygen mainly due to the high surface tension of the melt and the low thermal conductivity. In the application area of rotating components for aero engines, inertia friction and electron beam (EB) welding are common practices to join axially symmetrical parts [3]. 2876

The goal of the present work was to investigate the microstructural changes of Ti-6246 due to the inertia friction and the EB-welding process and to two post-weld heat treatments.

2 Experimental

Material for the investigation was taken from a closed die-forged compressor disk. Specimens of β- processed and fully heat treated Ti-6246 material (910°C/ 1 h + 595°C/ 8h) were joined by inertia and by electron beam welding. For the inertia friction welding two round specimens with an inner diameter of approximately 10 mm and a wall thickness of 7 mm and in case of the electron beam welding two plates with a thickness of approximately 7 mm were joined using standard welding parameters for these processes. The microstructure in the welded zone was investigated by optical microscopy and transmission electron microscopy. In addition to the as-welded condition, the effects of two post-weld heat treatments (PWHT) were investigated (595°C/ 2h and 640°C/ 2h). Besides microstructural investigations tensile, creep, and load controlled low cycle fatigue tests were performed.

3 Metallurgical Characterization

All metallurgical characterization was made on blocks cut perpendicular to the joining plane. The changes in the microstructure where characterized using optical microscopy (OM) and transmission electron microscopy (TEM).

The typical platelet-like primary αp-formation of a β-forged microstructure with a pancake-like grain form and a discontinuous α-layer along the grain boundaries is shown for the base material in the two optical micrographs in Fig. 1, whereas the TEM-micrograph in the same figure shows the high volume fraction of secondary αsec-platelets in the β-matrix between the

Figure 1. Microstructure of β-forged Ti-6246 base material, a) OM, b) OM and c) TEM 2877

Fig. 2 compares the inertia friction weld with the electron beam weld, both in the condition with the post-weld heat treatment of 640°C/ 2h.

Figure 2. Overview of inertia friction weld (left) and electron beam weld (right)

On each of the optical micrographs in Fig. 2 specific features of each joining process are visible. Characteristically for the inertia friction weld are the flash formation by the material squeeze out and the very fine microstructure directly in the weld plane. Typical for the EB-weld are the V-form, here from left to right, and the elongated grains with the same orientation as the β-grains in the base material. A detailed examination of the inertia friction weld (Fig. 3), conditions without a PWHT and with the PWHT of 640°C/ 2h, reveals that there are four zones, each showing specific changes in the microstructure.

Figure 3. Microstructural changes in the inertia friction weld, optical micrograph

The following changes occur in the inertia friction weld (distances measured from the middle of the weld) and are detectable by optical microscopy. From the center to a distance of about 175 μm (Zone I) the microstructure consists of recrystallized β-grains with a size of approx. 20 μm, from 175-275 μm (Zone II) of recrystallized β-grains with an approximate size of 10μm, and deformed β-grains ( size > 20μm) elongated in radial direction. Zone III from 275-525 μm consists of deformed β-grains ( size > 20 μm) elongated in radial direction. From 525-1500 μm (Zone IV) the original β-pancake microstructure (deformed) is visible. At distances greater than 1500 μm no influence of the inertia friction welding on the microstructure is detectable.

A conspicuous observation is that the former "αp-plates" of the base material are clearly visible by optical microscopy in Zone III. These "αp-plates" (Fig. 4a), however, are so-called "ghost α-plates". " Ghost α-plates" are former αp-plates of the base material which where in 2878

the β-phase field (T > Tβ, α+β → β) during the welding process, but time and temperature where not sufficient to reach chemical equilibrium (solid solution of β-phase).

Figure 4. "Ghost α-plates"

Further investigations were done by transmission electron microscopy. In the condition w/o PWHT small α-platelets are visible from a distance of 0-300 µm (Fig. 5a) whereas for distances of about 300-1500 μm (Fig. 5b) no small α-platelets were observed between "ghost α-plates" and non- dissolved αp-plates. The TEM observations showed that the "ghost α-plates" consisted of a high density of α-platelets (Fig. 4b). An additional PWHT leads to the precipitation of small α-platelets in the β-phase, the size and density increasing from the condition with the PWHT of 595°C/ 2h (Figs. 5c, 5e) to the condition with the PHWT of 640°C/ 2h (Fig. 5d). The precipitation of new small α-platelets is provable up to distances of approx. 1500 µm, due to the presence of two distinct sizes of α-platelets, "new" small ones and bigger ones. For distances greater than 1500 μm only the original α-platelets are present.

Figure 5. Microstructural changes in the weld zones, example inertia friction weld, TEM 2879

An example for a partially dissolved αp-plate is shown in Fig. 5e. The center is unaffected whereas the border was in the β-phase field and during cooling newer bigger α-platelets were formed (ghost structure).

Figure 6. Microstructural changes in the electron beam weld, PWHT of 640°C/ 2h, optical micrograph

In case of the electron beam weld (Fig. 6) the center of the weld consists of a very small zone with equiaxed β-grains (size 30-70 μm). Parallel to the weld one can see (Fig. 6) a "streak" on each side with a distance of approx. 700 μm to the weld-plane. The area in between the two "streaks" was probably melted. During the solidification elongated β-grains with the same orientation as the unmelted β-grains were formed. The microstructural changes as described above for the inertia friction weld are qualitatively observed in the EB-weld too, but at slightly bigger distances as compared to the inertia friction weld.

The disappearance of the "ghost" structure and the first appearance of non-dissolved αp-plates in the EB-weld happens at approx. 1250-1400 μm (inertia friction weld approx. 800-1000 μm) and the begin of the original base material structure is observed at a distance of approx. 1800 μm (inertia friction weld approx. 1500 μm). Furthermore, a higher volume fraction of α-platelets is formed in the melted zone of the EB-weld due to the lower cooling rate as compared to the inertia friction weld.

4 Mechanical Characterization

All mechanical testing was performed in such way that the load axis was perpendicular to the joining plane of the weld.

4.1 Tensile Tensile tests were performed for each condition of both welds at 20°C and 300°C. Fig. 7 compares these results with typical values of the Ti-6246 base material, the results of the welded conditions are plotted at test temperature in a range of +/- 10°C for better clarity. All conditions reach the level of the yield strength and the ultimate tensile strength of the base material (Fig. 7a). The elongation to fracture values are lower than the typical values of the base material (Fig. 7b). It should be noticed that the elongation values of welded specimens are per se lower when compared to un-welded specimens due to the difficulty to measure the true elongation. Cross sections perpendicular to the fracture surfaces of inertia friction welded specimens (Fig. 8) revealed that except for the specimens of the condition without a PWHT at room temperature all specimens failed outside of the weld and heat-affected zone in the base material. 2880

Figure 7a. Influence of the post-weld heat treatments on yield stress and ultimate tensile stress

Figure 7b. Influence of the post-weld heat treatments on the elongation to fracture

Figure 8. Cross-sections of tensile test specimens tested at room temperature (left) and 300°C (right), condition "inertia friction weld w/o PWHT", optical micrographs 2881

4.2 Creep The results of the creep tests at 450°C and a load of 650°C are listed in Table 1; all these results are from single tests. Compared to the base material all welded conditions showed in tendency a lower creep resistance, expressed by a lower value of tε=0.2% and a higher value of εpl,t=100h· In addition, both conditions without a PWHT showed a lower creep resistance when compared with their counterparts with a PWHT.

4.3 Low Cycle Fatigue Low cycle fatigue (LCF) tests have been performed for the conditions with a PWHT under load control at 300°C in air, an R-value of Rσ = 0.01, and a frequency of f = 1 Hz using a sinusoidal waveform. In Fig. 9 a comparison is made between these four conditions and against the fully heat treated Ti-6246 base material (910°C/ 1h + 595°C/ 8h). Specimens from the inertia friction welded material reach similar fatigue lives like un-welded specimen, whereas specimens from the EB- welded material show an up to 10 times lower fatigue life. Optical micrographs of cross-sections of broken specimens reveal that fracture in the inertia friction welded specimens (Fig. 10a) occurs outside the weld zone in the base material whereas in the EB-welded specimens fracture takes place in the weld zone (Fig. 10b).

Figure 9. Influence of the post-weld heat treatments on some low-cycle-fatigue properties, load-controlled LCF at 300°C / R = 0,01 / f= 1 Hz / air 2882

Figure 10. Cross-sections of fatigue test specimens tested at 300°C, 0-850 MPa

5 Conclusions

Weld specimens of the high strength near β-titanium alloy Ti-6246 in a β-forged condition for aero engine disk application where joined by inertia friction and electron beam welding. The following conclusions can be drawn from the performed microstructural investigations and the mechanical testing: • Both welding processes show qualitatively similar changes in the microstructure, which appear at greater distances from the weld for the EB-weld. The decisive difference, finer microstructure in the weld-zone for the inertia friction weld, is the result of the non- appearance of the liquid state during the inertia friction welding process. • A proper post-weld heat treatment is necessary to re-establish some degree of hardening in the weld zone and reduce residual stresses. Both PWHTs tested lead to the formation of

new αsec-platelets in the weld zone. • For the inertia friction welded specimens the refined microstructure in the weld zone and the PWHT lead to tensile and fatigue properties equivalent to the base material and to a slightly reduced creep resistance. • For the electron beam welded specimens the combination of small equiaxed grains in a 30-70 μm wide zone directly adjacent to the weld and elongated coarser grains in the weld zone plus the PWHTs lead to tensile properties equivalent to the base material, a slightly reduced creep resistance and a significantly reduced fatigue strength.

6 References

1. Materials Properties Handbook: Titanium Alloys (Eds.: R. R. Boyer, G. Welsch, E. W. Collins), ASM, Metals Park, Ohio, 1994, p.455 2. C. Sauer, G. Lütjering in Titanium'99 Science and Technology Proc. 9th World Conference on Titanium (Eds.: I. V. Gorynin, S. S. Ushkov), CRISM "Prometey", St. Petersburg, Russia, 1999, p. 390. 3. P. Adam, Fertigungsverfahren von Flugtriebwerken, 1st ed., Birkhäuser Verlag, Basel, Switzerland, 1998, p.165 The Influence of Manufacturing Anomalies on Fatigue Performance of Critical Rotating Parts in the Aero-Engine

W. D. Feist1, F. Niklasson2, K. M. Fox3 1MTU Aero Engines GmbH, München, Germany 2Volvo Aero Corporation, Trollhättan, Sweden 3Rolls-Royce plc, Derby, UK

Abstract

Manufacturing anomalies introduced during machining of critical parts have become a significant cause of gas turbine disc cracking events in the aero-engine. A European funded programme ‘ MANHIRP' has been set up to address this issue and some initial results from the programme, particularly those related to machining of titanium alloys will be presented in this paper. Three machining processes have been investigated: hole making, turning and broaching. For two of these processes, data are presented of fatigue response, where it can be seen that the anomalies introduced have reduced fatigue strength in most cases relative to datum specimens.

1 Introduction

The most common Hazardous Effect for aircraft engines as defined in the Joint Aviation Regulations (JAR-E) is uncontained high-energy debris being ejected from the engine. Critical parts are those, which have to achieve and maintain a high level of integrity to avoid Hazardous Effects and mostly consist of rotating high-energy discs and spacers. An analysis of events in service discs, which includes both cracking and burst, shows that manufacturing anomalies, mostly caused by machining abuse or rare events during machining, are rising and in the 1990s have become the biggest cause of disc burst. The ‘MANHIRP' programme is a Framework V Growth Programme set up to reduce the risk of disc burst from manufacturing anomalies. The key objectives of the programme are: • A scientific basis on which to control manufacturing process development, change and sentencing of non-conforming product in terms of the required surface condition in the materials. • The ability to specify process controls to achieve a specified low level of the risk of burst from machining anomalies. • A reduction in the probability of burst of a disc from a manufacturing anomaly by a factor of ten. 2884

The work in MANHIRP is examining three features of a disc which together account for nearly 90% of all reported causes of manufacturing anomalies. A schematic diagram showing typical locations of the above features is shown in Fig. 1. These features are:

(i) Turned surfaces, including the bore, diaphragm and drive arms. (ii) Holes, embracing those in the diaphragm, rim and in flanges. (iii) Broached slots in the rim of the disc.

Figure 1. Schematic diagram to show nomenclature and typical features in gas turbine discs.

2 Experimental Procedure

2.1 Hole Manufacture and Fatigue Testing in Ti6Al-4V A series of specimens were produced at Volvo Aero from a Ti6Al4V disc forging to specification PWA1228. An artificial technique was used to introduce 'overheating' type of anomalies (anomaly type 1[1]). This was carried out using an Electro Discharge Machining (EDM) process. This method was used to produce point anomalies using a 0.8mm thick by 2mm wide copper electrode. The fatigue samples were produced from titanium blocks with the dimension 110 x 40 x 25 (mm). A hole of diameter 7.5mm was rough drilled in the centre of the block. The EDM anomalies were then produced in the hole (Fig. 2). The EDM electrode removed approximately 0.5 mm. After the EDM the hole was rough drilled to achieve a smooth surface and to remove most of the re-cast layer produced by the EDM machining. To improve the surface roughness the holes were honed to remove approximately a further 0.2 mm on the hole diameter. After the honing the titanium block was sliced by wire EDM into flat fatigue specimens and then ground to remove re-cast layer from the wire EDM. `Datum' specimens were produced by drilling and honing alone. 2885

Figure 2. Point and line anomalies by EDM machining.

The fatigue specimens were of the dimensions shown in Fig. 3. The peak stress at the hole was calculated using handbook formulae and compared to prediction from ANSYS modelling. Fatigue testing was carried out at room temperature at a frequency of 1Hz using an R ratio (where R= maximum load/minimum load) of 0.1 and a sinusoidal waveform under load control. Fatigue testing was carried out using both an MTS and an INSTRON servo-hydraulic machine both with 100kN load cells and fitted with MTS647 hydraulic wedge grips rated to 100kN. Specimens were tested at predominantly two stress levels in order to establish scatter.

Figure 3. Schematic diagram of fatigue specimens used for hole feature testing. 2886

2.2 Turned Specimen Manufacture and Fatigue Testing in Ti6Al-4V A series of specimens were produced by MTU using Ti6A1-4V disc forging material to specification PWA1228. The specimens were machined from discs turned using similar turning parameters as specified in 2.2.1. The specimens were all tested according to the set up and details given in Fig. 4.

Figure 4. Fatigue testing set up used for 4 point bend testing

2.2.1 Datum Specimens These specimens were made using production turning parameters in order to provide a baseline. Tool geometry: CNMG 120412 with tool radius=1.2 cutting speed (vc)=90 m/min, feed (0=0.2 mm/rep, cut depth (ap)=0.3 mm. 2.2.2 Redeposited Material (anomaly type 6 [1]) These specimens were produced by taking a finish machined surface and introducing chip material between the specially prepared cutting insert and the machined surface while the disc was rotating. 2.2.3 Smearing by Contact of Tool Fixture with Rotating Work Piece (anomaly type 4[1]) These specimens were produced by pressing a tool fixture against the rotating surface of the disc. The aim of this work was to understand how deep the damage would be from this type of event during manufacturing. In fact the damage produced was very severe and would definitely be rejected during inspection. In future, it is intended to remove all visible damage by rework and assess the fatigue response of the remaining material. This surface condition would be more representative of real anomalies, which could occur during manufacturing. 2887

2.2.4 Chatter Marks (anomaly type 10[1]) Chatter marks were created by using a thin ring of 10-20mm thickness and clamping it into a three- jaw chuck and occurred in regions where the ring was not fully supported from the back. 2.2.5 Heavy Microstructural Deformation (anomaly type 1 [1]) This was intended to reproduce the effect of tool breakage, which typically produces locally distorted microstructure, locally increased residual stresses and/or adiabatic shear bands. This was done by punching the surface of the part using a pointless punch which produced adiabatic shear bands in the material. The geometric anomaly was then removed by reworking the surface.

3 Results and Discussion

3.1 Fatigue Testing of Hole Specimens in Ti6Al-4V Results of the fatigue testing of the hole specimens are shown in Fig. 5. It can be seen that specimens containing the 'overheating' anomalies generally have lower lives when tested at the same stress as 'datum' specimens.

Figure 5. Normalized fatigue results from specimens containing hole features tested at room temperature, R=0.1, frequency of 1Hz and sinusoidal waveform. Arrows indicate specimens which were unbroken at the cyclic life indicated.

Fractography has shown that the effect of overheating is to transform the alpha to beta phase in the local area. The rapid cooling effect of the surrounding material results in a 2888 transformed beta microstructure (see Fig. 6). At the very surface a recast layer is formed, and varying amounts of this layer remain after honing of the hole. If the total depth of overheated material is measured, there is some correlation between a larger depth of overheated material with a lower cyclic life of the specimen, particularly at the higher stress level employed.

Figure 6. Micrograph of overheated area taken through fracture surface of specimen tested at normalized stress of 0.875 which failed at 34,971 cycles.

3.2 Fatigue Testing of Turned Specimens in Ti6Al-4V Results of the fatigue testing are shown in Fig. 7.

Figure 7. Low cycle fatigue results from turned specimens in Ti-6A1-4V.

3.2.1 Datum Specimens The datum specimens can be seen to exhibit fairly typical S-N type behaviour. 2889

3.2.2 Redeposited Material (anomaly type 6 [1]) Redeposited material can be seen to reduce the fatigue strength below that of the datum specimens. In some cases, fatigue crack initiation started from smearing features (see Fig. 8), but in other cases initiation started from 'scratch' like features which were associated with the smeared material due to the artificial method used to create the redeposited material.

Figure 8. Fatigue crack initiation site associated with redeposited material.

3.2.3 Smearing by Contact of Tool Fixture with Rotating Work Piece (anomaly type 4[1]) Examination of the specimens after fatigue testing revealed that pre-cracks existed in the smeared material even prior to fatigue cycling and therefore fatigue life consisted of crack propagation only ( Fig. 9). This explains the very large debit on fatigue strength caused by this anomaly.

Figure 9. Scanning electron microscope image showing fracture surface, where heavily distorted microstructure showing boundary between 'forced' pre-crack (present prior to fatigue testing) and fatigue crack growth during fatigue testing. 2890

3.2.4 Chatter Marks The fatigue debit resulting from chatter is expected to be related to the increased surface roughness and/or changes in surface residual stress, which have not yet been investigated. Note that these specimens were well outside any acceptance criteria or standard usually employed to assess these anomalies. Nevertheless the chatter marks were not crack initiating as all fatigue cracks started at the specimens edges. Efforts are currently underway to avoid edge cracks on future tests. 3.2.5 Heavy Local Microstructural Deformation The fatigue debit from specimens turned containing heavy local microstructural deformation was unexpectedly low. It expected to be due to local tensile residual stresses concentrated around the tool impact area. However, as for the case of chatter marks, the specimens here failed from edge cracks and are undergoing further investigation.

4 Conclusions

From the fatigue data presented, it can be seen that anomalies typical of those, which can be produced during disc manufacture, can give rise to a fatigue deficit. Other work in this programme is focused on quantifying and improving the detectability of these anomalies by NDI techniques and also detecting them during the machining operation by the use of process monitoring (e.g. power and force monitoring, acoustic emission, vibration, and acceleration). Results from this work cannot be included here due to space restrictions.

5 Acknowledgments

The work presented in this paper forms part of a European Commission 'GROWTH Programme Research Contract "MANHIRP — Integration of Process Controls with Manufacturing to produce High Integrity Rotating Parts for Modern Gas Turbines", Contract Number G4RD-CT2000-00400 5 GROWTH Programme' and financial support from the European Community is gratefully acknowledged. Input from all the MANHIRP partners to this report is also acknowledged, in particular Mr. Paul Parkin from Rolls-Royce plc. for fatigue testing of the hole specimens and Ms. Inga Crössmann from MTU Aeroengines GmbH for fatigue testing of turned specimens.

6 References

1. K. M. Fox, MANHIRP Internal Document No. MANHIRP-01-0000006-WP1-RPT, issue 3, 2002 Development of Ti 6-2-4-6 Engine Discs

G. Terlinde, T. Witulski, G. Fischer Otto Fuchs KG, Meinerzhagen, Germany

Abstract

The alloy Ti-6A1-2Sn-4Zr-6Mo (Ti-6-2-4-6) has been developed for high strength and high fracture toughness applications and is used for engine compressor discs and blades at temperatures up to 450 °C. The best combination of properties can be achieved by β- processing of this alloy. In this case the last forging step (i. e. the final die forging) is performed in the β-field and the final properties are strongly influenced by the forging and heat treatment parameters. In a basic study the influence of the process parameters like temperature, strain, strain rate and the influence of billet grain size on microstructures and properties such as strength, fracture toughness and low cycle fatigue (LCF) were investigated. The results are discussed with particular emphasis on the influence of the microstructure on crack initiation during LCF-testing. With the results of the study and the support of FEM-simulation of the forging process it is possible to develop a processing window to achieve optimal properties in forged engine discs.

1 Introduction

The alloy Ti-6Al-2Sn-4Zr-6Mo (Ti-6-2-4-6) has been developed for application in engine compressors up to temperatures of 450 °C. It offers an attractive combination of high strength and fracture toughness as well as good creep resistance and good low cycle fatigue (LCF) properties [1-5]. These advantages have lead to an increasing replacement of Ti-6-2-4-2 and Ti-6-4 by Ti-6-2-4-6 with a significant weight saving. Ti-6-2-4-6 is a metastable ß-Ti-alloy that can be aged by secondary α-phase [1]. In order to achieve the desired combination of strength, fracture toughness, creep resistance and LCF properties it has to be forged above the beta-transus temperature (beta forging) [2]. During the beta forging process a number of metallurgical reactions take place that are influenced by the process parameters [2-5]. Important process parameters are the holding time at forging temperature, the forging temperature itself, the deformation degree and deformation rate as well as the cooling after forging. In order to optimize the forging process and to develop a "processing window" for a reproducible production process a systematic study was performed [6]. Pancake forgings were made with a systematic variation of the following parameters: • beta grain size before forging • degree of beta deformation • quench delay before water quenching after forging 2892

In addition, one of the heat treatment parameters, the cooling rate after solution treatment, was also varied. The evaluation included macro / microstructure, tensile properties, fracture toughness, creep and low cycle fatigue properties at higher temperatures. In this report some of the results with special attention to LCF properties are presented and discussed.

2 Experimental Methods

Pancake forgings with a thickness of 50 mm were produced in one heat starting from round billet with a diameter of 200 mm. The chemical composition was 2.0 Sn, 6.0 Mo, 4.0 Zr, 6.0 Al, 0.05 Si, 0.07 Fe, 0.11 O, 0.002 N, < 0.01 C, rest Ti [wt %]. In order to achieve coarser grain sizes the forging billet was heat treated above the beta transus for different times before beta forging. The beta grain sizes were determined by the lineal intercept method according to ASTM E112. The degree of deformation was varied by different starting thicknesses of the billet. The quench delay was varied by different holding times between the end of beta forging and water quenching of the pancakes. The heat treatment was as follows: solution treatment: 915 °C / fan cool (oil quench) aging treatment: 595 °C 8 h / air cool Tensile tests were performed at room temperature and 450 °C. The LCF-properties were only tested at 450 °C with load control at R = 0 and a trapezoidal wave form at f = 0.25 Hz. All specimen positions were tangential around the midthickness of the pancakes. The fracture

toughness KIc was determined on CT-specimens with a thickiness of 25 mm (C-R position). Macro- and microstructures were investigated on heat treated samples by optical mcroscopy (radial-axial plane, midthickness). Fractography on LCF-specimens was performed by SEM.

3 Results

3.1 Influence of Forging Strain The non-deformed condition as a reference was produced by beta-annealing a billet simulating the heat up to beta forging and then heat treating the billet like the pancakes. The microstructures for the different degrees of deformation (q) are shown in Figs. 1 and 2. In Fig. 1 at a low magnification the expected change from an equiaxed to a heavily stretched grain shape is clearly visible as well as a beginning recrystallization at the grain boundaries. Higher magnification reveals for the undeformed condition a fine needle type primary α precipitation in the grain and a widespread decoration of the grain boundaries with α-films (Fig. 2). Some side plate formation at the grain boundaries is also visible. At an intermediate forging strain the grain boundaries have developed a zig zag pattern by the deformation and accordingly the grain boundary α-phase shows the same pattern. At higher strains the grain boundary a looks even more discontinuous, and there appears to be a trend for increased side plate formation. 2893

Figure 1: Grain shape at different forging strains (as forged).

Figure 2: Microstructure at different forging strains (heat treated).

The tensile properties (RT) as a function of forging strain φ are shown in Fig. 3. While yield and tensile strength are not influenced by φ both the elongation to fracture A5 and the reduction of area Z increase with increasing forging strain from 4 % to 10 % or 6 % to 24 %, respectively.The same trend is observed at 450 °C. Fracture toughness increases slightly with increasing forging strain from 65 MPa√m at φ = 0 to 73 MPa√m at an intermediate strain and remains at this level at higher strain (Fig. 4). The LCF results are described in Fig. 5. From the LCF curves for each forging strain a stress was determined at which 105 cycles were achieved without failure. This life time is a typical requirement from an engine specification. The maximum stress for achieving 105 cycles to failure starts from 780 MPa in the non forged condition, reaches a maximum of 840 MPa at an intermediate strain and then continuously falls to 720 MPa at very high forging strains. The data point with the highest strain (open symbol) was taken from an actual forging. A special fractographic examination by removing the material up to the point of crack start showed that crack initiation took place at or near grain boundaries (Fig. 6). It is assumed that the cracks can form both at grain boundary α 2894 phase and within regions with side plates that develop along the grain boundaries and form a long area with a single crystallographic orientation.

Figure 3: Tensile Properties as a function of Figure 4: Fracture toughness as a function of forging strain. forging strain.

Figure 5: LCF strength at 450°C for 105 cycles as a function of forging strain

Figure 6: Crack location in LCF sample at or near grain boundary. Upper half of the photo shows the cross section of the sample, the lower half the perpendicular area of the sample. 2895

3.2 Influence of Beta Grain Size The starting grain sizes in the billet before beta forging were 0.45 mm, 0.6 mm and 0.8 mm. For the grain size variation the beta forging strain was kept at an intermediate level. Yield and tensile strength are similar for the different grain sizes. Elongation to fracture A5 and reduction of area Z exhibit a trend to lower values at coarser grain size (Fig. 7) (hot tensile test). Fracture toughness does not change measurably for the grain sizes investigated. The LCF strength for 105 cycles to failure at 450 °C shows a significant drop from 820 MPa to 700 MPa with increasing grain size (Fig. 8).

5 Figure 7: Tensile properties as a function of Figure 8: LCF strength at 450°C for 10 cycles as function grain size in the samples. a function of grain size in the samples.

3.3 Influence of Transfer Time / Quench Delay The quench delay between the end of beta-forging and the subsequent water quench was varied between 13 s and 125 s. For this investigation the forging strain and grain size were kept constant. The microstructure for the shortest quench delay shows a very fine distribution of α-needles and discontinuous grain boundary α-phase (Fig. 9). After the longest quench delay coarser α-needles are observed, and considerable amounts of side plates have formed.

Figure 9: Microstructures for different transfer times to water quench after forging. 2896

Both the tensile properties and fracture toughness were not significantly influenced by the variation in transfer time. The LCF strength for 105 cycles at 450 °C, however, drops from about 810 MPa to 740 MPa when increasing the quench delay from 13 s to 125 s (Fig. 10).

Figure 10: LCF strength at 450°C for 105 cycles as a Figure 11: Grain size model [1]. function of transfer time.

3.4 Influence of Cooling Rate after Solution Treatment Two halves of a pancake were solution treated and then quenched differently, one in oil, one on a fan. The microstructures are very similar on an optical microscopy scale. The effect of the different cooling rate on properties is shown in Tables 1 and 2. Increasing the cooling rate by oil quenching leads to a drop in elongation to fracture and reduction of area. The increase in yield strength is about 100 MPa at room temperature and about 50 MPa at 450 °C. Fracture toughness is reduced from 72.8 MPa√m to 54.9 MPa√m. The LCF strength increases from 760 MPa to 800 MPa. 2897

4 Discussion

The results have shown that the forging parameters can have a major influence especially on the fracture related properties. In particular, the LCF-strength appears to be very sensitive. The cooling rate after forging also leads to significant changes in the mechanical properties including strength. Subsequently an attempt is made to correlate the observed microstructures and properties and to come to conclusions about an optimised processing window. The effect of forging strain on the microstructures is complex. Starting from the undeformed condition with increasing strain the more or less continuous grain boundary α films form much shorter sections by the zig-zag type deformation of the grain boundaries. The effective slip length is reduced. For tensile fracture this leads to a transition from intergranular to transgranular failure with an improved ductility. The same transition in fracture mode takes place for fracture toughness specimens. The soft continuous α-film acts as low energy path for crack growth leading to a low fracture toughness. A crack profile investigation showed a reduced roughness with increasing forging strain. This should lead to a reduced toughness but is probably overcompensated by the benficial contribution from the change in fracture mode from intergranular to transgranular. The LCF strength for 105 cycles apparently passes through a maximum at intermediate forging strain. For all forging strains the crack initiation was found at or near grain boundaries (grain boundary α or side plates). This fracture mode has been already found by Sauer and Lütjering and is explained on the basis of a dislocation pile up model [1]. Starting from an almost continuous decoration with a soft grain boundary α film and a corresponding easy crack nucleation the films develop the already described zig- zag pattern with increasing beta deformation, and the effective slip length is strongly reduced leading to an increased resistance to crack initiation. The drop in fatigue strength with further increasing forging strain can be explained on the basis of a change in grain shape. Lütjering, Sauer et al. [1, 8] have recently developed a model explaining the directionality of fatigue strength. It starts from hexagonal stretched grains and from crack initiation at the grain boundaries by a dislocation pile up model (Fig. 11). Fatigue crack initiation is favored if long stretched grain boundary sections are positioned 45° to the applied load, since in this case a maximum shear stress and a long slip length develop. This basic model for effective slip lengths can be also used for discussing the effect of different stretching degrees and sizes of grains. It has been shown in this study that the effective slip length of grain boundary sections in an angle to the applied load continuously increases with increasing degree of stretching. The angle between these sections and the load, however, becomes smaller. These oberservations have opposing effects on the stress peak induced by a dislocation pile up. Since quantitative evidence has not been produced it has assumed that the increase in effective slip length favoring early crack nucleation overcompensates the reduction in shear stress by the reduced angle. An increase in beta grain size leads to a reduction in ductility and in LCF strength at 450 °C (see Figs. 7 and 8). As already discussed in context with forging strain effects the crack initiation preferentially takes place at or near grain boundaries for example through side plate areas. With increasing grain size the length of such areas increases leading to larger initial crack sizes and reduced ductility and LCF strength. With an increased quench delay after forging the material temperature drops further below the beta transus temperature before quenching and an increased α-formation at grain boundaries, from grain boundaries (side plates) and as relatively coarse α-needles in the 2898 matrix take place (see Fig. 9). Especially the increased side plate formation is regarded as detrimental for the LCF-strength since it favors early crack nucleation. An increased cooling rate after solution treatment by oil quenching instead of fan cooling improves tensile and LCF strength but lowers ductility and fracture toughness (s. Tables 1 and 2). Although not investigated in this study it is presumed that the higher quench rate leads to a finer precipitation of secondary α-phase similar to other metastable Ti-alloys. With the increased matrix aging the strength differential between the soft primary α-phase and the aged matrix increases resulting in early crack nucleation in the tensile and fracture toughness test. For the stress controlled LCF test the increased aging leads to a smaller plastic strain amplitude and therefore to an increased fatigue life. The results can be directly used to optimize the beta forging and heat treatment process. They also show that a rather tight process control is necessary to keep the properties in a technically acceptable range: • limited holding times in the heating furnace before beta forging • minimum forging strain and limited degree of grain stretching usually resulting in lower and upper limits of forging strain • limited delay between beta forging and quenching • controlled cooling rate after solution treatment with lower and upper limit Since in a complex forging because of heat loss and friction on the surface and because of the complex shape very different local temperatures and strains develop it is advisable to design the forging process by finite element forging simulations.

5 References

1. C. Sauer, G. Lütjering: Thermomechanical Processing of High Strength Beta Titanium Alloys and Effects on Microstructure and Properties, Journal of Materials Processing Technology 117 (2001), p. 331 2. A.K. Chakrabati, R. Pishko, G. W. Kuhlman: Growth Rate Optimization of Ti-6Al-2Sn- 4Zr-6Mo Alloy Forgings, in "Microstructure, Fracture Toughness and Fatigue Crack Growth Rate in Ti-Alloys, TMS Warrendale, USA, 1987, p. 231 3. H. Yano, Y. Tsumori, T. Matsumoto, Y. Yasui, T. Nishimura: Effect of Processing and Heat Treatment on the Mechanical Properties of Ti-6Al-2Sn-4Zr-6Mo Alloy, in "Titanium Science and Technology, Munich", Germany, 1984, p. 507 4. G. Chapuis, I.F. Uginet: Comparison of different beta forging process on Ti 6246 alloy, in Titanium '99: Science and Technology, St. Petersburg, CRISM, p. 1641 5. W.W. Cias: Phase Transformation Kinetics, Microstructures and Hardenability of the Ti-6A1-2Sn-4Zr-6Mo-Titanium Alloy, Report 27-71-02, Climax Molybdenum Company, 1972 6. P. Imgrund: Diploma Thesis, 2002, Technical University Clausthal, Germany 7. C. Sauer, G. Lütjering: Influence of α Layers at β Grain Boundaries on Mechanical Properties of Ti-Alloys; Mat. Sci. Eng. A319-321 (2001), p. 393 TiAl — New Opportunity in the Aerospace Industry

D. Roth-Fagaraseanu1, F. Appel2 1Rolls-Royce Deutschland, Dahlewitz, Germany 2GKSS Research Centre, Geesthacht, Germany

Abstract

Although the tremendous potential of gamma Titanium Aluminides (γ-TiAl) alloys has been consistently demonstrated for engine applications, the benefits have yet to be realised in production hardware. World wide research and manufacturing process development has focused on both: casting and hot working processes. Where the casting route has shown limited success so far, a production route has been established for manufacturing of compressor blades by hot working routes. The manufacturing knowledge gained and the materials data generated in this programme make TiAl technology a realistic prospect for future applications, significantly enhancing the competitiveness of actual products. However the introduction of a new material into service includes more aspects then the availability of the technology. An additional significant aspect is the establishment of supply chains able to produce a competitive product in regard to costs and quality compared to actual technology. This paper reviews the benefits of using TiAl in engine application with special focus on the compressor blades and addresses the actual status of the TiAl technology in aerospace.

1 Introduction

Gamma titanium aluminides have been in development for more than 20 years and show the potential to replace some Ni-base components. The target applications include blades and vanes in the high pressure compressor, large turbine blades, exhaust components, combustor chambers, casings etc. For each application a process route must be developed to achieve the component- specific requirements while maintaining low cost to increase the potential of commercialisation. Gamma alloys are light weight, high stiffness, high temperature materials that are inherently low cost and can be used to produce components using essentially the standard titanium or nickel processes. Component weight can be reduced by up to 50% in many cases, provided that provisions for the alloys' marginal ductility are made. The technical challenges associated with developing low density gamma titanium aluminides as viable engineering materials are numerous. However, the significant payoffs offered by the TiAl material system far outweigh the complex development efforts. 2900

2 Titanium Aluminides in Rolls-Royce

2.1 Alloy Compositions Rolls-Royce has been involved in the development of gamma titanium aluminides since the 1980s. Early efforts were aimed at improving oxidation resistance in this material system over the original P&W developed alloy, Ti-48Al-1V [1]. The result of this work led to the invention of a lightweight superior alloy Ti-46Al-5Nb-1W [2] for application on turbine and compressor rotating airfoils for high performance engine designs. More recently high Nb containing alloys have been developed at GKSS in Germany and show superior properties over all other compositions investigated in terms of flow stresses, creep resistance and oxidation behaviour. This alloy class with the composition Ti- 45Al-(5-10)Nb with small additions of B or C is also known as the TNB family [3-5]. Based on the superior properties, Rolls-Royce selected the TNB alloy for further evaluation.

2.2 Process Development The activities were concentrated on development of both casting and forming processes for rotating and static components. The casting process has been focus on the development activities for components like turbine blades, structural components and vanes in the high pressure compressor. However the casting process showed limited success so far in achieving an acceptable production level in terms of quality and scrap rate. In wrought alloy form, Rolls-Royce has successfully fabricated gamma compressor blades for AE3007 commercial fan engine applications. These blades were electrochemically machined from extruded bar stock using the production tooling employed for bill-of-material Inconel 718 (Figure 1).

Figure 1: Early efforts to produce small compressor vanes in TiAl. The picture is showing AE3007 14th Stage Compressor Blades manufactured by ECM Using Production Tooling These early manufacturing trials showed the high potential of γ-titanium aluminides in compressors, however the process route is suitable only for small and simple geometries. The latest Rolls-Royce development programme is focused on modem hot working routes for forged compressor blades and vanes. These activities represent the most advanced processing routes with the highest potential for aerospace applications to date. To achieve this target a highly competitive team including experts from the industry (GfE, Thyssen, Leitritz and Rolls-Royce Deutschland), supported by the research institute GKSS and contributions from the Universities of Dresden and Cottbus have collaborated to develop and demonstrate the manufacture of compressor blades in TiAl on an industrial scale. 2901

The processing includes raw material production by ingot metallurgy and powder production, primary forming processes by canned extrusion or pancake forging, near net shape hot forming by isothermal forging, heat treatments, NDT techniques and machining / ECM operations to the final geometry. Each single step in the process route has been optimised and characterised by detailed mechanical testing and metallographic investigations. A schematic overview over the process investigated in this study is shown in Fig. 2.

Figure 2: Schematic overview of the processes investigated for the production of compressor blades

3 Industrial Hot Working Route for γ-TiAl Components

Small quantities of γ-titanium aluminide components have often been produced and successfully tested in relatively aggressive environments. However, before manufacture of γ-titanium aluminide parts on a production scale can be started, a deep understanding of the problems related to the process scatter and their effects on components integrity needs to be addressed. A considerably effort within the program has been focused on the transfer of the technology developed on small scale into an industrial production environment and towards the understanding and quantification of the natural process scatter. The success of TiAl manufacturing is strongly related to the use of a narrow processing band. In the following the development and selection of the single steps in the process route are described.

3.1 Ingot Production and Ingot Qualities The ingot production was found to be a critical processing step, especially if ingots of large diameters are necessary. Good quality ingots are available up to 200mm diameter. Smaller ingots are more homogeneous than the larger ones. One problem is macroscopic pores, which could not be completely closed by hot working and can even lead to cracking of the material 2902 during forging. For this reason the ingots in this program were subjected to hot isostatic pressing at 1200°C, 200 MPa for 4 hours. Existing pores in the ingots persist during the following process steps and are difficult to close during the forming processes. Fig. 3 shows an example of defects in an extruded bar coming from the ingot production.

Figure 3. Defects found in γ-titanium aluminides in extruded bar.

The most severe problem, however, connected with ingot production is macro- and micro segregations of Al, because the mechanical properties depend on the Al content. As opposed to defects like pores, the variation in element concentration due to segregation mechanisms can be completely removed by subsequent forming processes. However the non-uniform ingot microstructure and the poor failure resistance of TiAl alloys make hot-working of ingot material difficult. Research in this field has made significant progress in the last few years and the problems associated with large-scale wrought processing are now being overcome. This has been the subject of a number of excellent reviews [6,7].

3.2 Powder vs Ingot Metallurgy

Hot working routes using raw material in powder form is widely used in the industry for the production of critical components like discs or complex shaped components. The benefit of using powder metallurgy is the homogeneous fine microstructure of the components and the possibility of efficient material usage by consolidating the powder to suitable geometries. Negative aspects of the powder production method are the associated gas porosity, which needs to be removed by HIP- processes and ceramic inclusions resulting from the powder production method. Additionally γ-TiAl ingots have been often reported [8-10] to have a coarse and inhomogeneous microstructure consisting of lamellar colonies with grain sizes of several millimetres. To break down the microstructure a hot process route consisting of at least two forming steps is needed to achieve a high quality product in terms of homogeneity and properties. Powder metallurgy was considered at the beginning of the program as a means of overcoming these problems. In addition the reduced flow stresses for powder products as a result of the refined microstructure was considered in order to allow a forging process at lower temperature and move from isothermal forging towards more economic processing like conventional forging. The starting microstructure for the forging operations produced from powder consolidation process and ingot manufacture are shown in Fig. 4 for a TAB alloy with the composition (at.%) Ti-47Al-3.7 (Nb, Cr, Mn, Si)-0.5B. 2903

Figure 4: Microstructure for a TAB2 alloy: a) in a VAR (vacuum arc remelted) ingot and b) in a powder metallurgical manufactured and through HIP consolidated bar.

The pictures are underlining the expected differences in microstructure quality with a much higher homogeneity and microstructure refinement for the powder route. Despite the beneficial microstructure for the powder route, the associated gas porosity, which in particular cases could not be closed completely by the HIP processes, has been found to be detrimental to mechanical properties. Additionally, flow stresses cannot be reduced sufficiently to allow hot working operations at temperatures suitable for conventional forging. Because of the higher costs associated with this process the powder route has been deselected from the program.

3.3 Hot Working Routes Using Extrusion and Isothermal Forging Apparently, the most critical step is to convert the coarse grained, textured and segregated microstructure into a more homogeneous and workable structure that is suitable for secondary processing. Primary ingot break-down was accomplished by extrusion at a temperature of 1250°C, which is about 90° below the below the α-transus temperature. Under these conditions severe oxidation and corrosion occurs, thus, the work piece was encapsulated in austenitic steel. Extrusion below Tα led to duplex microstructures with coarse and fine grained banded regions. Nevertheless, the microstructural refinement obtained in the primary wrought material reduced the susceptibility to cracking in secondary hot working steps and allowed the material to be worked by closed-die forging. Extruded material can be also used directly for the manufacturing of the blades by ECM / machining operations without any further forming steps. Compared to the manufacturing of the blades by isothermal forging, the material in this case has been extruded to a higher extrusion ratio (1:10) in order to achieve a fine fully recrystallised microstructure. To minimise raw material usage, rectangular tooling was used, which had been previously optimised for the blade geometry. In a secondary working step the blade geometry was produced by forging in a temperature range between 1000°C and 1150°C utilizing two sets of impression dies. Using optimal secondary forging conditions, more than 200 blades were successfully produced. After forging a substantial improvement of the microstructural homogeneity was observed both in the blade aerofoil and the root compared to the as-extruded material. 2904

Figure 5: Extruded bars in γ-TNBV2 alloy. The left picture shows the canned bars after extrusion. The picture on the right side shows the cross section of the bars with optimised geometry.

Figure 6: γ TiAl blades produced by isothermal forging and ECM/final machining

3.4 Extrusion vs. Isothermal Forging Route for Manufacture of Compressor Blades A direct comparison between the extrusion route (extrusion + final machining) and the forging route (extrusion + isothermal forging + final machining) must include cost aspects. While the extrusion route uses more raw material and therefore includes more machining time, the forging is associated with better material homogeneity and material properties but is the more time and energy consuming route. From the cost point of view this assumption is true only for conventional materials. For the gamma alloys there are two aspects in the processing route, which need to be considered when selecting the proper production route: - γ alloys are still a niche product with, compared to the conventional alloys relatively low production volumes. As a result γ-TiAl are still expensive materials compared to conventional alloys. - For conventional materials the high ductility exceeding 20% at room temperature is reflected in a high flexibility in the selection of machining operations. This results in the ability to selects cost effective machining steps with high material removal rates. For γ alloys the material brittleness restricts the machining operations to "material friendly steps" with relative low removal rates per pass. This problem demands pre-shaping operations to minimise the material volume to be machined out. In the case of machining out of the extruded bar the material yield is about five times lower than the near net shape process. Additionally the removal of the capsule material necessary for the extrusion operation leads to further time consuming steps. An analysis of the two production routes including these two aspects above indicates the manufacture of the blades by isothermal forging to be the most attractive route not only from the microstructure quality point of view but also in terms of production costs. 2905

3.5 Near Net Shape Forging vs. Precision Forging The two processes described above have been assessed in parallel by manufacturing small serial production batches and comparing the sequential operations in each route including also the cost aspects. Because of the highly competitive market in the aerospace, only a cost competitive route enhances the introduction potential of the new technology and motivates the design community to take advantage of the new product. A comparison between the actual component price in IN718 design and a γ component manufacture by near net shape process reflect a 2 to 2,5 time's higher costs for the γ technology. This is far too much to be balanced by the benefits associated with use of γ titanium aluminides. Starting from the near net shape technology and taking into account the high raw material costs and limited flexibility in the machining operations the logical step forward is the manufacturing of the blades by precision forging. The only way to achieve this target is a higher temperature during the forging operations. With the technology available for the conventional materials this step is not possible due to the following two problems: - The high flow stresses of the γ-alloys require a higher temperature to achieve a processing window for precision forging. This temperature can not be achieved with the actual die material ( Mo-dies) - At the forging temperature the die material are to soft and due to the plastic deformation only a limited number of components can be produced within the required component tolerances. For a precision forging of the γ-alloy the demand is towards higher temperature dies, which can allow a process window close to the α-transus or above. The development within the described program focuses at the development and test of high temperature dies as a key technology for the precision forging of γ-alloys.

4 Conclusions and Outlook

At this stage of the programme a hot working route for γ titanium aluminides compressor blades at industrial scale has been successfully demonstrated. This was only possible within a highly skilled team, joining industry and research competence. The most promising manufacturing route has been identified to be ingot production, primary forming step by canned extrusion, isothermal forging and final machining / ECM. For the powder route only small benefits have been identified over the ingot route, which are overshadowed by a loss in mechanical properties and increased production costs. The successful manufacture of γ-blades in an industrial environment has lead to the selection of this material to enter the validation phase for engine application. The technology developed in this program is part of the engine demonstration packages E3E and ANTLE which will qualify the γ- technology for realistic industrial introduction. However before serial production can be started some further work is needed to achieve a competitive cost compared to the current products. The necessary steps to achieve this target have been identified to be a precision forging operation and the related changes in the process route. A break-through event in the industry for titanium aluminide technology to be competitive with Ti- of Ni-base technologies can only be achieved with a broad application spectrum. This target is only possible with a continuous long-term activity including 2906 development and implementation of new innovative γ-TiAl specific processes like torsional forging.

5 Acknowledgements

The authors are grateful to all project partners from GKSS, GfE, Thyssen, University of Cottbus and Dresden for their contribution to the success of the program and for the many valuable discussions and support. Financial support by the German Federal Ministry for Education and Research ( 03N3065) is gratefully acknowledged.

6 References

1. M.J. Blackburn and M.P. Smith, AFML-TR-79-4056, May 1979 2. S.K. Jain et.al., US Patent No. 5,296,056,1994 3. Paul JDH, Appel F, Wagner R. Acta Mater 1998;46:1075 4. Appel F, Oehring M, Wagner R, Intermetallics 2000;8: 1283. 5. Appel F, Oehring M, Paul JDH, Lorenz U. In: Hemker KJ, Dimiduk DM Clemens H, Darolia R, Inui H, Larsen JM, Sikka VK, Thomas M, Whittenberger JD, editors. Structural intermetallics. Warrendale (PA): TMS; 2001. p. 63. 6. Semiatin, S.L. (1995). Gamma Titanium Aluminides (eds Y-W. Kim, R. Wagner, M. Yamaguchi). TMS, Warrendale, PA, p. 509. 7. Semiatin, S.L., Seetharaman, V., and Weiss, J. (1998). Mater. Sci. Eng. A243, l. 8. Martin PL, Rhodes CG, McQuay PA. In: Darolia R, Lewandowski JJ, Liu CT, Martin PL, Miracle DB, Nathal MV, editors. Structural intermetallics. Warrendale (PA): TMS; 1993. p. 177. 9. Brossmann U, Oehring M, Lorenz U, Appel F, Clemens H. Z Metallkd 2001; 92: 1009. 10. Brossmann U, Oehring M, Appel F. In: Hemker KJ, Dimiduk DM, Clemens H, Darolia R, Inui H, Larsen JM, Sikka VK, Thomas M, Whittenberger JD, editors. Structural intermetallics. Warrendale (PA): TMS; 2001. p. 191. Titanium Matrix Composites for Demanding Structural Aerospace Applications

C. Leyens, J. Hausmann, J. Hemptenmacher DLR-German Aerospace Center, Cologne, Germany

Abstract

Titanium matrix composites (TMCs) are attractive light-weight materials for aerospace applications with strength and stiffness about twice as high as monolithic titanium alloys. At moderately elevated temperatures TMCs offer high creep resistance. The maximum service temperature is essentially limited by the matrix material, thus titanium aluminides based on orthorhombic Ti2AlNb might be capable of broadening the application of TMCs towards higher temperatures. Designing components with these anisotropic materials generally requires a systems approach taking into account the specific advantages and drawbacks of the composite material in order to optimize the reinforcement strategy and provide reliable and still affordable high performance components.

1 Introduction

Titanium matrix composites (TMCs) have been developed as high performance materials for light weight structural applications. The materials are comprised of a silicon carbide (SiC) fiber embedded in a titanium matrix, thus making use of the high strength of the SiC fibers (typically of the order of 4000 MPa), their high stiffness and creep resistance at elevated temperatures combined with the damage tolerance of titanium alloys (Fig. 1). Although not yet used as series products, TMCs have successfully proven their capabilities in niche applications giving rise to expectations for a wider range of applications in the near future. Among others, a major hurdle for application are the high costs of materials fabrication but also some technical issues have to be solved for particular applications. Especially for aerospace applications, safety issues are of great concern, therefore reliability of TMCs has to be demonstrated for the specific components in the future.

2 Compressor Applications

As described above, there is an increasing need in future compressor design for light-weight, high-performance materials. TMCs are considered as candidate materials for such applications where particularly high strength and stiffness are needed. Today, research and development are focussed on reinforcement by TMCs of two different compressor components. The aforementioned reinforcement of airfoils is likely to be limited to fan blades, since the payoff is highest for these large and highly loaded blades. Fig. 2a shows an example 2908

Figure 1: Metallographic cross-section through a SiC-reinforced titanium matrix composite. The typical diameter of the fibers is 140 gm, a typical fiber volume fraction is of the order of 40%.

of a fan blade locally reinforced by SiC fibers. The fibers are introduced where stresses are highest, aiming at improving the stiffness of the thin-walled airfoils thus increasing their aerodynamic load capabilities. A second type of target component for TMC application is the compressor disk. Fig. 2b illustrates the so called blisk (=bladed disk) compressor design which is intended to be replaced by bladed rings (blings). Enormous weight savings associated with replacement of the heavy disks by SiC fiber reinforced rings are a key driver for the development of these components. For this technology, the availability of TMCs appears to be a prerequisite since monolithic titanium alloys will not be capable of withstanding the loads imposed on the rings during service. In addition to weight savings, the bling technology is expected to beneficially influence the dynamics of the rotor, thus resulting in further performance improvements [1]. Unlike the fan blades, the downstream stages of the bling are subjected to higher temperatures which might be of the order of up to 700°C, thus making use of the high temperature capabilities that TMCs offer, provided that a suitable matrix material is selected. Notably, SiC fiber reinforced blings as well as vanes and blades have been successfully tested in the USA, Germany, Japan and in the UK as part of extensive research and development programs, however, have not gone into series production yet. Nevertheless, these tests have proven the high potential that TMCs offer for compressor applications.

Figure 2: (a)Advanced titanium fan with local SiC fiber reinforcement. (b) In future compressors, today's blisk technology (=bladed disks, left) might become replaced by the bling technology (=bladed rings, right). Blings require SiC reinforced titanium matrix composites. Picture courtesy MTU Aero Engines. 2909

3 Fabrication of High Quality TMCs

Basically three routes have been established for the fabrication of TMCs: 1) The foil-fiber-foil technique is making use of fibers being placed between thin titanium foils and consolidated by hot pressing. The major drawbacks of this technique are the relatively poor uniformity in fiber distribution and its limitation to those matrices which are available as thin foils. 2) The mono tape technique relies on the fabrication of prepreg tapes. The tapes are typically produced by plasma spraying the titanium matrix onto unidirectional arrangement of several fibers. The tapes can be easily stacked and consolidated. The fiber distribution is better than for the foil-fiber-foil technique. 3) Highest quality TMCs can be achieved using the matrix coated fiber technique (Fig. 3). Among the various deposition processes available, electron beam physical vapor deposition (EB-PVD) and magnetron sputtering have been used to deposit coatings of the matrix material onto the monofilaments. Since the best coating quality can be achieved with the sputtering technique, all results presented in this paper are obtained from matrix coated fiber fabricated TMCs using magnetron sputtering. After matrix deposition the coated fibers are arranged in a component preform and consolidated by hot isostatic pressing. The resulting TMCs microstructure reveals a highly homogeneous fiber distribution (see Fig. 1) which is a prerequisite for excellent materials properties. After consolidation the preforms can be machined using conventional methods for the machining of monolithic titanium alloys and titanium aluminides. The consolidated composite is comprised of four major components: 1) the 140 µm SiC fiber containing a tungsten or carbon core which does not contribute to the mechanical properties of the fiber, 2) a 3 µm carbon protective coating that is present on the fiber on delivery to protect the fiber against the aggressive titanium matrix, 3) a reaction zone between the carbon coating and the titanium matrix which is preferably below 1 µm in thickness, and 4) the titanium matrix. It is the properties of the single constituents and their interaction during processing and service that largely influences the properties of the resulting composite. The fiber volume fraction of the composite can be easily adjusted by the coating thickness during titanium matrix deposition. Obviously, the fiber volume fraction is closely related to the mechanical properties of the composite which will be outlined in the following section.

Figure 3: Schematic of the DLR processing route for TMCs fabricated by the matrix coated fiber technique. 2910

4 Properties

Selected properties of the major constituents of a typical TMC system are given in Table 1. The strength and the stiffness as well as the density of the composite can be easily calculated using a simple rule of mixture. For a typical fiber volume content of 40% and a composite density of 4 g/cm3 an ultimate tensile strength of 2.3 GPa and a Young's modulus of 226 GPa can be achieved. Although strength and stiffness can be further increased by utilizing a higher fiber volume content in real components the overall fiber volume content will be mostly lower than 40%, since in practice, components will be reinforced locally where stresses are maximum. This will be particularly the case for the SiC-reinforced fan blades shown in Fig. 2a, where local rather than integral reinforcement of the blade provides optimum performance.

Table 1. Properties of a typical TMC comprised of SiC monofilaments and a titanium matrix.

4.1 Tensile Strength and Stiffness High tensile strength and stiffness of unidirectionally reinforced TMCs are the most outstanding properties which have been the key drivers for the development of TMCs. Fig. 4 compares the specific strength and specific stiffness of various engineering materials, indicating that, on a density corrected basis, TMCs outperform all metal alloys with regard to

Figure 4: Specific Young's modulus vs. specific strength of various aerospace materials demonstrating the high potential of TMCs [2]. 2911 both, strength and stiffness, thus making them very attractive for aero engine usage [2, 3]. In the low temperature range, fiber reinforced plastics (FRP) offering even higher specific strength and specific stiffness are the major competitors for TMCs, however, special precautions have to be taken if used, for example, as fan blades, since the erosion resistance of FRP is usually poor. As a result of unidirectional reinforcement, the properties of TMCs are anisotropic with best performance along the fiber elongation. Notably, strength and stiffness anisotropy is not as pronounced as for FRP (Fig. 4), however, optimum use of TMCs is achieved by unidirectional loading. Fig. 5 shows the current temperature limit for different titanium alloys used as matrices in TMCs and their respective room temperature tensile strength values. The maximum service temperature of TMCs mainly depends on the temperature capability of the matrix material, since the SiC fiber itself is stable up to temperatures in excess of 800°C. High temperature exposure not only affects the mechanical properties of the matrix material but can also cause environmental degradation of the titanium alloys by oxidation and oxygen/nitrogen embrittlement. Therefore, depending on the anticipated service temperature range selection of the matrix alloy is crucial. Furthermore, it appears obvious that the ultimate high temperature capability of the respective alloys can only be achieved if protective coatings are available which are currently under investigation for these applications [4-8]. While Ti-64 and Ti-6242S/TIMETAL 834 might eventually be used at up to 300 and 600°C, respectively, orthorhombic matrices appear to have the potential to push the temperature limits towards 650 to 700°C. Although processing of TMCs with intermetallic orthorhombic matrices is more complicated compared to conventional matrices, optimization of the fabrication steps resulted in high quality defect-free composites (Fig. 6). Notably, ultimate tensile strength shows only limited dependence on the matrix material (Fig. 5), indicating that higher temperature capabilities of orthorhombic alloys do not result in reduced mechanical capabilities. In addition, the strength of the composite is dominated by the strength of the fibers. Thus, a sufficient ductility of the matrix material is important which, in contrast to gamma TiAl and Ti3Al matrices, can be achieved by orthorhombic alloys. Moreover, for elevated service temperatures, interface stability between the matrix and the fiber becomes increasingly important. While at ambient service temperatures reaction between the matrix and the fibers occurs during the consolidation process only and can be

Figure 5: Approximate service temperature limits (gray columns) for TMC components and room temperature ultimate tensile strengths (white columns) of the composites. 2912

Figure 6: Metal graphic cross-section of a defect-free fully consolidated orthorhombic TMC.

effectively blocked by the thin carbon coating applied to the fibers (Fig. 1), the reaction between the matrix and the carbon coating may proceed at higher temperatures, thus finally leading to highly detrimental fiber-matrix reaction. It appears that orthorhombic titanium aluminides may be one key to solve this problem since they show less reaction with the carbon coating, making them promising candidates for use at moderately elevated temperature matrices in TMCs.

4.2 Fatigue Behavior and Residual Stresses For fan blade applications, the fatigue resistance of the material is a major design criterion. Therefore, the fatigue behavior of TMCs has been extensively investigated. For elevated temperatures, relevant for blade and vane applications in the high pressure part of the compressor, the fatigue resistance of the TMC exceeds that of the unreinforced matrix material by more than 100% in both, the low cycle fatigue (LCF) regime and the high cycle fatigue (HCF) regime (Fig. 7). However, at room temperature, high stresses can be allowed in the LCF regime, while in the HCF regime, the fatigue resistance is significantly reduced and even falls below that at 600°C. The reduction in fatigue resistance is attributed to the presence of matrix cracks due to the limited ductility of the titanium matrix at ambient temperatures while at higher temperatures the matrix is more ductile.

Figure 7: Fatigue behavior (R=0.1) of SiC/TIMETAL 834 at RT and 600°C [9]. 2913

Figure 8: Effect of residual stress modification on the fatigue behavior (R=-1) of TMCs [10].

Residual stresses are a second factor contributing to the reduced fatigue resistance at ambient temperatures. Due to the thermal mismatch between the titanium matrix and the SiC fiber, compressive stresses in the fiber and tensile stresses in the matrix occur after cooling down from consolidation temperatures. At higher service temperature, relaxation processes in the matrix reduce the residual stresses and thus, along with the higher matrix ductility, result in higher fatigue strength. In particular load cases, residual stresses may even play a more important role. For example, for tension-compression loading (R=-1), the fatigue limit of the TMC is well below that of the unreinforced matrix material [10-11]. Stress relaxation, e.g. by pre-straining of the matrix prior to testing can substantially reduce the residual stresses and thus improve the fatigue behavior of the TMCs (Fig. 8). About 40% improvement has been achieved so far, however, using more sophisticated relaxation procedures may further improve fatigue resistance of the TMCs under tension-compression loading conditions at ambient temperature [10].

4.3 Designing with TMCs Designing a real component such as a fan blade using TMCs requires a systems approach considering, among others, materials properties and limitations, reliability and fabricability issues as well as costs. It is therefore clear that reinforcement will be applied locally where needed rather than across the entire component. FEM analysis of the stresses likely to occur during service helps to identify the areas to be reinforced. Safety requirements for aircraft engine parts require a conservative design which can still benefit from the mechanical capabilities of TMCs. Obviously, these and many more issues to consider make the use of TMCs a real challenge for aerospace applications, however, the expected payoffs are very high and thus further drive the interest in these materials. 2914

5 Conclusions

Outstanding mechanical properties such as high strength, stiffness, creep and fatigue resistance make long-fiber reinforced titanium matrix composites (TMCs) ideal materials for demanding high technology applications, e.g. in aeroengines. Due to extremely high materials costs and lack of knowledge on materials properties their use has yet been limited to niche applications. Even here, TMCs compete against alternative materials and must prove their advantages, particularly to justify the high materials costs. While today most TMC applications are focussed on low or moderately elevated temperatures, high temperature applications are likely the future of TMCs. In this range of applications, TMCs are in direct competition to nickel-base alloys and steels, where they are expected to expand the application spectrum of titanium alloys and titanium aluminides towards higher mechanical loads and temperatures.

6 References

1. K. Steffens, A. Schäffler, 2002, MTU Aero Engines, München. 2. J. Kumpfert, M. Peters, U. Schulz, W.A. Kaysser. in Gas Turbine Operation and Technology for Land, Sea and Air Propulsion Power Systems, Ottawa, Canada, 1999 3. J. Kumpfert, K. Weber, H.J. Dudek, C. Leyens, W.A. Kaysser, in European Conference on Spacecraft Structures, Materials and Mechanical Testing, Braunschweig, Germany, ESA, SP-428. 4. C. Leyens, M. Peters, W.A. Kaysser, in Titanium '99: Science and Technology, Vol. II, CRISM "Prometey", St. Petersburg, Russia, 1999, p. 866. 5. C. Leyens, M. Peters , W.A. Kaysser, Advanced Engineering Materials 2(5), 2000 p. 265. 6. C. Leyens, M. Peters, P.E. Hovsepian, D.B. Lewis, Q. Luo, W.-D. Münz, Surf. Coat. Technol. 155(2-3), 2002, p. 103. 7. C. Leyens, M. Peters, P.E. Hovsepian, D.B. Lewis, Q. Luo, W.-D. Münz, in Materials for Advanced Power Engineering , Vol. I, Liege, Belgium, 2002, p. 465. 8. C. Leyens, R. Braun, P.E. Hovsepian ,W.-D. Münz, in Gamma Titanium Aluminides, TMS, Warrendale, PA, 2003, in press. 9. J. Hemptenmacher, P. Peters, H. Assler and Z. Xia, in EUROMAT '99, Vol. 5, 1999, p. 190. 10. J. Hausmann, J. Hemptenmacher, C. Leyens, W.A. Kaysser, in Fatigue 2002, EMAS, West Midlands, UK, 2002, p. 1915. 11. J. Hausmann, C. Leyens, J. Hemptenmacher, W.A. Kaysser, Adv. Eng. Mat. 4(7), 2002, p. 497. Burn Resistant Titanium Alloy (BuRTi)

W. E. Voice Rolls-Royce plc, Derby, UK

Abstract

A new burn resistant beta titanium alloy (BuRTi) has been successfully developed in the UK. Its properties are competitive with those of conventional alpha + beta titanium alloys yet with a better ductility and a temperature capability up to at least 500°C. The alloy chemistry has been modified to minimise cost through the use of commercially available master alloys. It could potentially replace a large proportion of the steel and nickel components currently used to protect against titanium fires in the compressor to give a ~30% weight reduction. A burn resistant titanium component will be demonstrated on the ANTLE demonstrator engine next year where it is will help to improve engine efficiency and minimise fuel burn. The characteristics of this BuRTi alloy will be presented together with a comparison of its properties to those of other alloys such as the high-temperature alloy Ti679.

1 Introduction

The beta stabilised Burn Resistant Titanium alloy known as BuRTi was designed through a DTI LINK programme with the University of Birmingham UTC/IRC. The objective was to develop a titanium based alloy that does not burn under the gas temperatures and pressures experienced in the Intermediate Pressure (IP) and High Pressure (HP) sections of the compressor. It was also aimed that the alloy and processing route should be cost competitive whilst offering potential weight saving advantages over existing materials. Thin sections of conventional titanium alloys will burn in air when ignited by a localised high heat source such as friction heating due to a heavy rub. Titanium alloys are therefore restricted to rub-free components or to lower pressure and temperature rotors that need to be isolated between non-burning steel stators when in the IP compressor. Increasing the burn resistance of titanium alloys will permit use as casings, compressor stators and rotors thus displacing steels and nickel alloys of almost twice the density. The burn resistance properties have been improved through alloy chemistry and are derived from a number of aspects; the production of copious, mainly vanadium, oxide during burning which snubs out fire by preventing oxygen reaching exposed alloy; the reduction in melting temperature so that the alloy burns in a liquid state; reduction in frictional heating due to rubbing at high temperatures; higher thermal conductivity and specific heat. BuRTi contains 25% vanadium, 15% chromium and, significantly, 2% aluminium which permits commercially available alumino-thermically produced master alloy to be used for melting to reduce costs. The initial material made from master alloy was found to be brittle due to a modest content of around 1200ppm oxygen that was also residue from the alumino-thermic reaction [1]. The patented innovation by Birmingham University [2] was to add a 2916 relatively high level of carbon (0.2%) that improves the material in two ways; the oxygen is scoured from the alloy matrix by tying them into carbide precipitates and then the resultant carbide particles constrain grain size during processing, [3].

2 Processing

An on-going compressor blade programme will use 50mm diameter bar-stock made from 100kg ingots that have been reduced by forging and rolling. Processing has so far shown that blade aerofoils can be either forged or electrochemically machined whereas roots can be ground, milled or broached. For ANTLE, compressor blades will have forged aerofoils and high-speed milled roots because this is economically appropriate for making small batches. These components will be run in the demonstrator aero-engine in 2004. Physical and preliminary mechanical property data were determined for a plasma arc melted 150mm diameter ingot subsequently extruded to 47mm bar and given the standard heat treatment of 600°C for 2 hours. Note that there is unpublished evidence to show that forged BuRTi has mechanical properties superior to those of extruded material so the comparison to forged Ti679 below is expected to be an underestimate of BuRTi capabilities.

3 Physical Properties

Figure 1. Comparison of BuRTi Thermal Conductivity with Ti679 and IN718.

The Elastic Modulus of BuRTi at room temperature, EBuRTi=118GPa, is high compared to conventional titanium alloys, especially for a beta alloy (ETi679=105GPa), and this is excellent for blade applications as it directly affects frequency of vibration. The Thermal Conductivity 2917 is higher than Ti679 at lower temperatures and at operating temperatures conductivity approaches that of nickel alloys, Fig. 1, which is beneficial to burn resistance as heat is more rapidly removed from the potential fire source. Thermal Capacity is also beneficial rising from 550 J.kg-1.°C at 100°C to 650 J.kg-1.°C at 500°C compared to just 480 J.kg-1.°C and 570 J.kg-1.°C for Ti679. One small -3 drawback is the density of BuRTi which is slightly higher at ρBuRTi = 5,100 kg.m compared to ρTi679 = 4,840 kg.m 3. The burn resistance of a range of titanium alloys was demonstrated by attempting to ignite 1 mm x 25mm x 50mm coupons using an arc-welding torch. The conditions imposed were 300°C, 695kPag air pressure and 150m.s-1 air velocity which are typically found in the IP compressor. Fig. 2 shows gamma titanium aluminide which does not burn under these conditions, and Ti6/4 which rapidly burns down to the grips. BuRTi exhibits an intermediate level where it catches fire but quickly extinguishes itself, the coupon eventually breaking in half due to repeated attempts to ignite it. The copious formation of vanadium oxide is suspected to be a major factor in extinguishing fire.

Figure 2. Comparison of Burn Resistance between Different Titanium Alloys using 1 x 25 x 50mm coupons at 300°C, 695kPag air pressure and 150m.s-l air velocity.

4 Mechanical Properties

The maximum temperature of operation for conventional BuRTi bar is considered to be 500°C so as to limit coarsening of the alpha particles precipitated during heat treatment. Fig. 3 shows that although strength at ambient temperature is slightly lower than the conventional high temperature alpha+beta titanium alloy Ti679, BuRTi retains significant strength to beyond 550°C. This is put into context when compared against nickel alloys and steels in Fig. 4 where specific strength (density related) shows it to be much higher to make it a very competitive material. The alloy has a particularly high ductility (>20%), Fig. 5 which should be beneficial to FOD resistance and containment. Fatigue strength of BuRTi is improved at elevated temperatures as shown in the high cycle fatigue curve of Fig. 6 whereas the rival Ti679 alloy follows the normal reduction in fatigue life with temperature such that at 450°C BuRTi is better. The improved fatigue is due to a change in fracture characteristics at around 200°C, depending on grain size [4]. Creep resistance of BuRTi is significantly better than Ti679 as shown by the time and stress to achieve 0.1% strain at different temperatures in Fig. 2918

7. There is also an interesting anelastic creep phenomenon at lower temperatures and higher stresses, Fig. 8 which may be similar to that observed in aluminium alloys [5]. Mechanical properties therefore confirm that BuRTi is a strong contender for compressor applications at temperatures between 200 and 500°C in the aero-engine

Figure 3. Comparison of BuRTi Tensile Strength with Ti679.

5 Associated Work

Other work has been carried out to confirm the suitability of BuRTi for aero-engine compressor applications. The resistance to impact damage and subsequent fatigue response [6] was found to be comparable to that of Ti-6/4 where both alloys exhibited ductile deformation during ballistic impact and subsequent fatigue loading demonstrated inverse proportionality to firing pressure. An investigation into the surface integrity of the bum resistant titanium alloy after high speed milling and creep feed grinding has shown that considerable surface damage is introduced associated with the break up of large, hard carbide particles [7]. However there were no corresponding microstructural changes and no significant effect on fatigue life. 2919

Figure 4. Comparison of BuRTi Specific Tensile Strength with Other Alloys.

Figure 5. Comparison of BuRTi Tensile Elongation with Ti679. 2920

Figure 6. Comparison of BuRTi HCF Life with Ti679, Kt=1.

Figure 7. Comparison of BuRTi and Ti679 Creep to 0.1% Strain at 450°C. 2921

Figure 8. Anelastic Creep of BuRTi during testing at 400°C/700MPa (interrupted tests).

6 Summary

The BuRTi alloy as so far passed all criteria for HP compressor blade applications; its physical properties are as good or more beneficial than the competitor alloy, mechanical properties are superior at service temperatures, and it shows no signs of being notch sensitive after impact or machining damage. Just as important is that it has an economic processing route suitable for blade manufacture from bar stock by forging and machining. BuRTi is also a metallurgically interesting alloy in that demonstrates phenomena such as anelastic creep and a change in fracture mechanism from ambient to service temperatures. This has spawned a number of investigations that are a rich vein of material understanding, as exhibited by the number of publications arising in this area.

7 Acknowledgements

Many thanks for the innovative work carried out by the Rolls-Royce University Research Partners and the meticulous material testing undertaken by Timet. 2922

8 References

1. Y.G. Li, P.A. Blenkinsop, M.H.Loretto, N.A. Walker, Mat.Sci. & Tech., 15, 1999, 151. 2. Y.G.Li & P.A. Blenkinsop, European Patent No. EP1002882B1. 3. Y.G. Li, P.A. Blenkinsop, M.H.Loretto, D. Rugg, W.E.Voice, Acta.Mat., 47, 1999, 2889. 4. T. Udomphol, W.E. Voice M. Wenman, P. Bowen, 'Micromechanisms of Fracture in Ti- 25V-15Cr-2A1-0.2C Alloy', Ti-2003 Conference. 5. R.W. Evans, P.J. Scharning, Mat. Sci. & Tech., 17, 2001, 1. 6. M.R. Bache, W.J. Evans, W.E. Voice, Mat. Sci. & Eng. A333, 2002, 287. 7. D. Novovic, D.K. Aspinwall, R.C. Dewes, W.E. Voice, P. Bowen, 'Surface Integrity of a Burn Resistant Ti alloy (Ti-25V-15Cr-2A1-0.2C wt.%) after High Speed Milling and Creep Feed Grinding', Ti-2003 Conference. Author Index

A B Abiko, T. 253 Baccalaro, M. 3345 Ablitzer, D. 149 Bache, M. R. 675, 2409 Abramov, E. 1737 Backes, G. 2785 Addison, R. 329 Bacos, M.-P. 2277 Adley, M. 929 Bae, Y.-I. 3067 Adrian, D. 2455 Baker, M. 839 Aeby-Gautier, E. 1091, 1171, 1599 Bakow, L. 1053 Aindow, M. 1535 Balitskii, A. I. 2975 Aiyangar, A. K. 2019 Banerjee, D. 2137 Akahori, T. 1683, 3181, 3269 Banerjee, R. 533, 1389, 1413, 1559, 2547 Akhonin, S. V. 197, 213 Banerjee, S. 533 Albering, J. H. 979 Baquey, C. 3173, 3331, 3353, 3369 Albrecht, J. 431, 3213 Barber, J. 2943 Alcalá, G. 891 Bareille, R. 3173, 3331 Alexis, J. 2455 Bars, J. P. 957 Alpay, S. P. 1535 Barshinger, J. N. 297 Altenberger, I. 1059 Bartels, A. 2123, 2385, 2401 Amélio, S. 2377 Barthe, N. 3331 Anacleto, N. 121 Bártová, B. 2059 Ando, S. 1933, 1973 Baudin, T. 1345, 1377 Andrei, M. 2075 Baumann, A. 3339 Andreyev, A. Y. 135 Baur, H. 2123, 3411 Ankara, A. 1831 Baxter, C. F. 2935 Ankem, S. 2019 Baxter, D. 651 Anoshkin, N. F. 13 Bayles, R. A. 2083 Ansel, D. 957, 1323, 3173, 3369 Beck, U. 3339 Appel, F. 2123, 2317, 2899 Beck, W. 2689 Appolaire, B. 1091, 1171 Becker, P. 3339 Araoka, A. 2153 Beeley, N. R. E 2503 Archambault, P. 1599 Béguin, J. D. 2455 Ariga, T. 769, 2983 Belaygue, P. 2455 Ariyasu, N. 3141 Belin, C. 3369 Arvieu, C. 2487 Bell, T. 867, 921, 2433 Asami, K. 3285 Benedetti, M. 1659, 1957 Aspinwall, D. K. 883, 2185, 2817 Bennett, J. 173 Aubertin, F. 2555, 3315 Bennewitz, K. 3051, 3059 Berdin, V. K. 313 Berestov, A. V 577 L Author Index

Berger, P. 913 Brillo, J. 411 Besenhard, J. O. 979 Briottet, L. 1485 Betsofen, S. Y. 349 Brooks, J. W 321, 471 Bettge, D. 2577 Broughton, R. 581 Bewlay, B. P. 297 Brouillaud, B. 3331 Beyer, E. 1001 Bruno, G. 1045 Beynon, J. H. 1243 Brynza, A. M. 135 Bhattacharyya, D. 533 Buchkremer, H. P. 463, 487 Biallas, G. 1949 Buhlert, M. 855 Biebricher, U. 205 Burghardt, B. 1965 Bingert, J. F. 2145 Burk, J. D. 2951 Birkbeck, J. C. 2761 Busongo, F. 1855 Blackburn, M. J. 1535 Busse, P. 3011 Blatter, A. 3307 Bystrzanowski, S. 2401 Blodgett, M. P. 1039 Byun, J.-Y. 745, 753 Blum, M. 205, 3011 Blümke, R. 823 C Bobrov, A. V. 2285 Cai, X. 1493 Bocher, P. 1291 Cai, Y. X. 503 Boehlert, C. J. 2145 Cai, Z. 3261 Bohm, K.-H. 683 Caiazzo, E 2651 Bondarchuk, V. 1879 Cailletaud, G. 1171 Bondareva, X. O. 495 Cammarota, G. P. 729 Bonilla, F. A. 891 Cano, P. 3111 Bonora, P. L. 2075 Carrasco, L. 3261 Bonss, S. 949, 1001 Carton, E. 619 Bossi, R. H. 455 Carton, E. P. 799 Boster, P. L. 2935 Chandra, D. 1421 Bowen, P. 1767, 2817, 2829, 2837 Chang, H. 1195, 1575 Bowry, M. 2837 Cheah, T. 589 Boyer, R. 549 Chellman, D. J. 2615, 2635 Boyer, R. R. 2615, 2643 Chen, J. 1195, 1575 Bozzolo, N. 1211 Chen, P. 503 Braceras, I. 987 Chen, R. 1519 Bram, M. 463, 487, 2555 Chen, Y. 419, 2355, 2479 Brandes, M. C. 2011 Chen, Z. 419, 2355 Braun, R. 2441 Chiba, A. 807 Bray, S. 2745 Chizhik, T. A. 2991 Breme, J. 2555, 3277, 3315 Chmielewski, A. 891 Brenner, B. 949, 1001 Choe, B. H. 1123, 1179, 1567, 1607 Brezner, M. 3261 Choi, J.-H. 1123 Bridier, E 1469 Chrapoński 2217, 2225, 2347 Author Index LI

Christ, E. 173, 1631 Doh, J.-M. 745, 753 Christ, H.-J. 1361, 1723, 1911, 2417 Doherty, R. D. 1429 Christodoulou, L. 357, 1187 Doi, M. 1075 Chung, S.-H. 753 Dong, H. 867, 921, 2433 Cihak, U. 2793 Dong, L. M. 2241 Civelekoglu, S. 2145 Dos Santos, J. E 2539 Clark, L. 1631 Drozdenko, V. 511 Clemens, H. 2123, 2301, 2385, 2401, 2793 Drummond, B. G. 3035 Coleto, J. 2495 Du, J. H. 899 Collins, P. C. 533, 1389, 2547 Du, Y. 1493 Connors, S. 1389 Duan, Q. W 479, 517 Cotton, J. D. 455, 2615, 2635 Duda, C. 2487 Crofts, P. 1807 Duo, P. 1667 Cui, Y. Y. 2241, 3245 Duret, N. 2667 Cui, Z. S. 715 Curcio, F. 2651 E Egry, I. 411 D Eifler, D. 3237 da Costa Teixeira, J. 1171 Eisenberg, S. 3051, 3059 da Silva, A. A. M. 2539 Eliaz, N. 3299 Dartigues, E 2495 Eliezer, D. 1715, 1737 Dashwood, R. J. 357, 1187 Emura, S. 2153, 2601 Daurelio, G. 2651 Engelko, V. 2777 de Groot, K. 3157 Erauzkin, E. 987 Decker, M. 1361 Eschler, P. Y. 3307 Degischer, H. P. 2531 Eßlinger, J. 2845 Dehm, G. 2401 Evans, A. D. 1045, 2801 Dekhtyar, O. I. 495 Evans, D. J. 1559 Delfosse, J. 1315 Evans, R. W. 1283, 1759 Deng, J. 285, 1815 Evans, W. J. 1283, 1759, 1807, 2003 Denis, S. 1171, 1599 Eylon, D. 1615, 1707, 1715, 1753, 1791, Dewes, R. C. 883, 2185, 2817 1799, 1941, 2761 Dewobroto, N. 1211 Di Iorio, S. 1485 F Dibert, G. 2737 Fafilek, G. 979 Diep, H. T. 1053 Faller, K. 3051, 3059 Dindorf, C. 823 Fang, L. 993 Ding, H. S. 439 Fanning, J. C. 181, 2643, 3027, 3125 Ding, R. 1267 Fedorova, L. V 707 DiPasquale, J. 2943 Feist, W D. 2883 Doege, E. 611 Feng, C. R. 2083 Dogan, B. 683, 1831 Feng, L. 365, 1639, 1645, 3083 LII Author Index

Feng, Z. C. 2169 G Feofanov, K. L. 135 Gach, E. 2713 Ferrero, J. 385 Gadow, R. 1009, 3345 Ferrero, J. G. 1543 Galeyev, R. M. 297, 313, 569 Fields, J. L. 2463 Gane, D. H. 1053 Fierlbeck, J. 3253 Gao, B. 337 Filip, R. 597, 971 Gao, Z. 861 Fischer, D. 213, 305 Garcia de Cortázar, M. 2495 Fischer, F. D. 2301 Gamier, S. 3369 Fischer, G. 1839, 2697, 2891 Gasser, P. 2523 Fischer, S. 2523 Ge, P. 1591 Fleck, C. 3237 Gebeshuber, A. 929 Floer, W 1911 Gemeinböck, G. 1445 Flower, H. M. 357, 1187 Genc, A. 2547 Ford, B. 2003 Gerling, R. 2123, 2385, 2401 Ford, S. J. S. 2975 Germain, L. 1291 Fouvry, S. 905, 1667, 1675 Germann, L. 2137 Fox, K. M. 2883 Gerosa, R. 1369 Fox, S. P. 81, 149, 321, 3027 Gey, N. 1291 Francillette, H. 1275 Gheorge, M. 1155 Franz, H. 3011 Gigliotti, M. F. X. 297 Fraser, H. 1413 Gill, S. J. 2083 Fraser, H. L. 533, 1389, 1559, 2547 Gilmore, R. S. 297 Friedrich, B. 2209 Ginatta, M. V. 237 Friedrich, H. 3393 Gittos, M. E 2091 Fritzen, C.-P. 1911 Glatzel, U. 847 Froes, F. H. 569, 1353, 2999 Glavicic, M. G. 1299, 1429 Fromentin, J.-F. 2487 Gloriant T. 1323, 3173 Frommeyer, G. 2249, 2293, 2331 Goetz, R. L. 1299 Frouin, J. 1753, 1799 Golan, E. 1737 Fu, H. Z. 439 Gollas, B. 979 Fuchikawa, S. 941 Goñi, J. 2495 Füchtmeier, B. 3253 Gordienko, A. I. 875 Fujii, H. 699, 737, 1107, 3075, 3197 Gordin, D. 3173 Fujishiro, S. 1615 Gorynin, I. V. 1 Fukai, H. 635, 691, 1147, 1847, 3181, Goto, Y. 3205 3269 Grauman, J. 2943 Fukui, Y. 1139, 3385 Grauman, J. S. 2107 Fukunaga, H. 2769 Greno, G. 1369 Furrer, D. 549 Grevey, D. 913 Furuhara, T. 1219 Griga, Y. 511 Furuta, T. 1519, 1527 Grosdidier, T. 1211 Author Index LIII

Guédou, J. Y. 2137 Héricher, L. 1091, 1171 Gueuning, D. 2673 Hernandez, I. 2393 Guichard, D. 1485 Herold, H. 659, 729 Guillemot, F. 3173, 3331, 3353, 3369 Herter, S. 2293 Guillou, A. 957 Hida, M. 1511 Gunawarman 1615 Hirano, K. 2585 Gundakaram, R. C. 2145 Hirata, T. 737 Günther, B. 2577 Hiromoto, S. 3173, 3285 Guo, H. Z. 603, 715 Hong, K.-T. 745 Guo, J. J. 439 Hong, Q. 2027 Guo, L. 3261 Honma, T. 3221 Guo, Z. X. 1267, 2503 Horvath, W 2713, 2853 Gurney, A. 2627 Hosoda, H. 1139, 3385 Güther, V. 2123 Hu, D. 1067, 2339, 2369 Hu, Q. M. 2177 H Hua, L. 589 Ha, W. 3067 Huchel, U. 935 Hadasik, E. 371 Hui, S. 337 Hadianfard, M. J. 2563 Humbert, M. 1291 Hagiwara, M. 1607, 2153, 2161, 2601 Hur, S. M. 1453 Haldenwanger, H.-G. 3393 Hutson, A. L. 1707 Hamel, J. 149 Hutt, A. 385 Hamentgen, M. 2555 Hwang, J. H. 1519, 1527 Hammer, J. 3253 Hyodo, T. 141 Hammerschmidt, J. 2209 Hyun, Y. T. 157, 1123, 1179, 1567 Han, M. C. 479 Hanawa, T. 3173, 3285 I Hanusiak, W. M. 2463 Ichihashi, H. 141 Hao, Y. L. 2177, 3189, 3245 Iguchi, T. 1235 Harada, Y. 627, 1031, 2201 Iguchi, Y. 2115 Harding, R. A. 411 Ikeda, M. 1203, 1583 Hardwicke, C. U. 297 Ikehata, H. 1527 Harper, M. 1559 Ikuhara, Y. 1527 Hattori, T. 2769 Imam, A. 1421 Hattori, Y. 3181 Imam, M. A. 1903, 2083 Hausmann, J. 2907 Imayev, R. 2317 Hausmann, J. M. 2593 Imayev, R. M. 2257 Hayashi, T. 3117 Imayev, V 2317 He, Y. 379 Imayev, V. M. 2257 Heidemann, J. 1957 Imtiaz, K. 1855 Helm, D. 69, 1839, 2753, 2845, 2875 Inamura, T. 1139, 3385 Hemptenmacher, J. 2067, 2577, 2907 Inoue, H. 1339 LIV Author Index

Inoue, K. 1583 Kaspar, J. 949 Inui, H. 2361 Kastorskij, D.A. 831 Ishii, M. 737, 1107, 3075 Katahira, K. 993 Ito, K. 1519 Kato, T. 993 Ito, M. 3261 Katsura, S. 3269 Itoh, K. 737 Kawakami, A. 1107 Ivashko, V V. 875 Kawakami, M. 221 Ivasishin, M. 495, 1227, 1259, 1307 Kawasaki, H. 3173 Iwamoto, C. 1527 Kawasaki, K. 941 Iwata, T. 2959 Kaysser, W A. 2593 Kelbassa, I. 2785 J Kestler, H. 2123, 2401 Jablokov, V. R. 3035 Keutgen, S. 2785 Jachowicz, M. 905 Khelifa, M. 1599 Jackson, M. 357, 1187 Khor, K. A. 589 Jahazi, M. 1291 Kiese, J. 3043, 3393, 3403 Januszewicz, B. 905 Kim, D. U. 793 Jarczyk, G. 3011 Kim, J. W. 157 Jardy, A. 149 Kim, K.-N. 3229 Jata, K. 2627 Kim, M.G. 447, 2233, 2265, 3067 Jeong, H. W. 1123, 1567 Kim, S. E. 157, 1179, 1567, 2361 Jha, S. K. 1887, 1895 Kim, S. J. 1179 Jia, J. 439 Kim, S. K. 3067 Jiang, Y. R. 1731 Kim, S. Y. 793 Jones, J. P. 1807, 2003 Kim, S.-E. 1123 Josso, P. 2277 Kim, S.-J. 1607 Jung, J.-Y. 745 Kim, Y. J. 2233, 2265 Jung, S. B. 793, 2265 Kim, Y.-J. 447, 3067 Juszczyk, B. 2225, 2347 Kimura, H. 2309, 3197 Kimura, S. 2115 K Kimura, Y. 3221, 3323 Kaczmarek, L. 905 King, A. 1045, 2801 Kalidindi, S. R. 1429 Kinoshita, K. 2923, 3075 Kalinuk, O. M. 197 Kirbs, A. 3339 Kalinyuk, A. N. 1259 Kitano, F. 1331 Kallee, S. W. 2867 Klotz, U. E. 2523 Kameyama, Y. 993, 3361 Knippscheer, S. 2249, 2293, 2331 Kaneko, M. 3117 Knyazeva, S. I. 707 Kanetake, N. 2511 Kobashi, M. 2511 Kar, S. 1413 Kobayashi, M. 3173 Karasev, E. A. 557 Kobryn, P. A. 1299 Karasevska, O. P. 1227 Koike, J. 1251 Author Index LV

Koike, M. 3261 Laptev, A. 487 Kojima, S. 3089, 3097 Larsen, J. M. 1887 Komatsu, S. 1203, 1583 Laudenberg, H. J. 3011 Komotori, J. 941, 993, 1025, 3205, 3361 Lavisse, L. 913 Kompan, Y. Y. 229 Lazare, S. 3369 Kong, E 419, 2355 Le Maitre, E 49 Koo, J. M. 793, 2265 Le, Q. H. 1405 Korb, G. 1437, 1445 Lee, C. G. 1179 Kosaka, Y. 3027 Lee, C. S. 1453 Kościelna, A. 2225, 2347 Lee, D.-G. 1453 Koster, U. 2075 Lee, H. G. 883 Kostrivas, A. 2091 Lee, J. H. 157 Kosugi, H. 1031 Lee, S. 1453 Koyama, K. 769, 1075 Lee, S.-H. 3067 Kozakai, T. 1075 Lee, T. H. 1179 Kozlov, A. N. 577 Lee, W B. 793, 2265 Kramer, M. 3403 Lee, Y. H. 1453 Kreutz, E. W 2785 Lee, Y. T. 157, 1123, 1179, 1567, 1607, Król, S. 1699 2361 Kronberger, H. 979 Leholm, R. 2627 Krull, T. 1871 Leitner, H. 2793 Krupp, U. 1911 Lemster, K. 2523 Kubatík, T. 2059 Lepetitcorps, Y. 2495 Kubiak, K. 371, 597 Lerf, R. 3307 Kübler, J. 2523 Levesy, B. 3149 Kukuchek, P. 2627 Levin, I. V. 577, 2285 Kullick, M. 2681 Levin, Y. S. 135 Kullmer, R. 929 Leyens, C. 2441, 2593, 2907 Kulp, S. 611 Li, C. 285 Kuramoto, S. 1519 Li, C. X. 2433 Kuramoto, S. 1527 Li, D. 329, 1115, 1925, 2177 Kuroda, D. 3173, 3189 Li, G. P. 1115 Kuroda, S. 3173 Li, H. 1195, 1639, 1645 Kuznetsov, A. 2317 Li, J. P. 3157 Kuznetsov, A. V. 2257 Li, J. Y. 2169 Li, M. 393 L Li, S. 3245 Labrugère, C. 3331, 3353 Li, S. J. 3245 Lach, E. 2377 Li, S. Q. 1499 Landua, S. 823 Li, S. X. 1925, 2241 Langlade, C. 913 Li, X. 1397 Lappe, W. 777 Li, Y. 643 LVI Author Index

Li, Y. L. 365, 2809, 2825, 3083 Maki, S. 1031, 2201 Li, Z. 337, 2041 Maki, T. 1219 Li, Z. L. 2169 Malinov, S. 1131 Li, Z. X. 899 Mall, S. 1039 Lian, Z. 393 Malysheva, S. P. 349 Liang, F. 3293 Manabe, T. 3269 Liang, J. 541 Mantani, Y. 1511 Liang, Z. F. 503 Mao, X. N. 2517 Lichtenberger, A. 2377 Marchal, Y. 2673 Liesner, C. 431, 2705, 3213 Marketz, W. 2301, 2531, 2713, 2793 Lindemann, J. 1823, 2425 Markovsky, P. E. 1131, 1227, 1259, 1307 Lindqvist, J. 2277 Marquardt, B. 1651 Lischka, J. M. 2293 Martin, B. 173, 329 Liskiewicz, T. 905 Martinez, S. A. 1039 Liu, C. L. 365, 2809, 2825, 3083 Martynov, M. A. 831 Liu, G. 1059 Marya, S. 49, 721 Liu, J. L. 165 Masaki, M. 699 Liu, J. R. 1925 Mascalzi, G. 2975 Liu, R. M. 1499 Masri, T. 2455 Liu, Y. 503 Mathon, M. H. 1345 Liu, Y. Y. 1115, 2177 Matsu, K. 2983 Liu, Z. J. 425 Matsukura, N. 3019 Lohse, G. 1361 Matsumoto, S. 3141 Lohse, G. M. 1723 Matsuoka, K. 2959 Long, M. 1691 Matsuoka, S. 1745 Lorenz, U. 1831, 2317 Matviychuk, Y. V. 1227 Loretto, M. H. 1067, 1477 Maurer, J. 1753, 1799 Luckowski, S. 173 Maximov, Y. A. 2967 Luft, A. 949 Mei, J. 541 Lugmair, C. 929 Meiners, W 525 Lundstrom, D. 2277 Memola Capece Minutolo, F. 2651 Lüthen, F. 3339 Mendez, J. 1469 Lütjering, G. 431, 1659, 1855, 1871, Metayer, S. 2455 1879, 1957, 1979, 2875, 3213 Meyendorf, N. 1791, 1941 Lütjering, S. 69, 1839, 2753 Mi, X. 861 Lyasotskaya, V. S. 707 Miao, W. 861 Lysenko, L. V. 2967 Mikuszewski, T. 2217, 2225, 2347 Mills, M. J. 847, 2011 M Minakawa, K. 635, 691, 941, 1025, 1147, Ma, Z. J. 2479 1847, 2585 Madariaga, I. 2393 Mine, Y. 1933, 1973 Maier, H. J. 1949 Mingler, B. 1445 Author Index LVII

Miodownik, A. P. 1397 Nicholas, T. 2761 Mitchell, A. 189 Nicolai, H.-P. 431, 2705, 3213 Mitsuda, Y. 261 Niinobe, K. 2325 Mitterer, C. 929 Niinomi, M. 95, 1615, 1683, 1707, 3181, Miyamoto, S. 39 3189, 3245, 3269 Miyamoto, Y. 769, 3019, 3103 Niklasson, E 2883 Miyazaki, S. 1139, 3385 Nishida, M. 807 Miyazawa, Y. 769, 2983 Nishida, Y. 343 Mizuno, E 3285 Nishino, K. 1519, 1527 Moiseev, V N. 229 Niwa, S. 3181 Moller, M. 3315 No, M. I. 2393 Mori, K. 627, 1031, 2201 Nochovnaya, N. A. 2777 Morita, M. 3221, 3323 Noda, T. 761, 3133 Morita, T. 941 Nomura, T. 1235 Morizono, Y. 807 Nonaka, T. 1527 Morri, A. 729 Noster, U. 1059 Motyka, M. 597, 1505 Notkina, E. 1979 Mueller, G. 2777 Novovic, D. 2817 Mukherji, D. 839 Muller, C. 823, 1919, 1965 O Münzer, R. 2853 Oda, T. 261, 2923 Murai, K. 3361 Oehring, M. 2317 Murao, T. 627 Ogata, T. 1745 Murashov, V. P. 135 Ogawa, A. 635, 691, 1025, 1147, 1847 Murty, K. L. 2033 Oguma, H. 1775, 1783 Oh, K.-T. 3229 N Oh, M. H. 2361 Na, J. K. 1753, 1799 Oh, M. S. 1099 Nagasako, N. 1527 Ohmori, H. 993 Nagashima, K. 3141 Okabe, M. 761, 3133 Naito, S. l075 Okabe, T. 3261 Nakagawa M. 1203 Okabe, T. H. 253, 261 Nakamura, T. 1775, 1783 Okamoto, A. 3019, 3103 Nalla, R. K. 1059 Okazaki, M. 2585 Nam, S. W 2161 Okuno, O. 3261 Nansen, D. S. 2463 Oldenburg, M. 1461 Narushima, T. 1235, 2115 Ong, T. S. 891 Nauer, G. E. 979 Ono, Y. 1745 Nerlich, M. 3253 Onzawa, T. 2983 Neuberger, B. W. 2019 Osawa, S. 1519 Neumann, H.-G. 3339 Ostapczuk, A. 891 Nicholas, E. D. 2867 Ostolaza, K. 2393 LVIII Author Index

Ostrovski, O. 121 Piper, K.-E. 305 Ottensmeyer, R. 855 Pirling, T. 1045 Ottonelli, F. 2651 Plath, P. J. 855 Ouchi, C. 1235, 1615, 2115 Pleszakow, E. 971 Over, C. 525 Pobol, I. L. 875 Oyama, H. 3089, 3097 Pokhmurskii, V I. 2975 Poletti, C. 2531 P Poprawe, R. 525 Pallu, S. 3331 Porté-Durrieu, M. C. 3331, 3353, 3369 Pan, Z. 393 Portella, P. D. 2577 Pao, P. S. 2083 Porter, R. L. 2099, 2951 Park, I. 253 Posse, O. 611 Park, J. K. 1099 Poths, R. M. 1243 Patankar, S. 589 Preuss, M. 2745, 2801 Pather, R. 321 Prilutsky, V P. 659 Paton, B. E. 667 Prima, F. 1323, 3173, 3369 Patrovsky, H. 929 Protokovilov, I. V. 229 Patterson, A. 2635 Puzakov, I. U. 2285 Paulin, C. 1667 Pautonnier, E 2471 Q Pavlov, V. 511 Qazi, J. I. 1155, 1651, 1691 Payan, S. 2495 Qi, Y. L. 2027, 2517 Paydar, M. H. 269 Qiu, S. Y. 1731 Paykin, A. 2777 Qu, H. 1639 Pederson, R. 1461 Qu, H. L. 1645, 2449, 2825 Pelayo, A. 3111 Quenisset, J.-M. 2487 Penelle, R. 1345, 1377 Quesne, C. 1345, 1377 Perez-Bravo, M. 2393 Quets, S. 2673 Perruchaut, P. 1667 Quinta da Fonseca, J. 2745 Perry, N. 721 Peters, J. O. 1659, 1957 R Peters, M. 2441 Rack, H. J. 1155, 1651, 1691 Peters, P. W. M. 2067, 2569, 2577 Raffestin, M. 2471 Petit, J. A. 2455 Rainforth, W M. 1243 Petit, P. 1275 Raoufi, M. 269 Petrunko, A. 511 Rauch, E. F. 1485 Petrunko, A. N. 135 Ravi Chandran, K. S. 1895 Phelps, H. 1631 Reclaru, L. 3307 Phelps, H. R. 455, 2635 Redjaïmia, A. 2377 Piekoszewski, J. 891 Reeves, J. W. 129 Pikulin, O. M. 213 Reguly, A. 2539 Pilchowski, U. 2719 Reissig, L. 847 Author Index LIX

Rendigs, K.-H. 2659 Saunders, N. 1397 Rey, C. 1315 Savvakin, D. G. 495 Richter, E. 891 Schaden, T. 2301 Ritchie, R. O. 1059, 1979 Schafler, E. 1445 Rivera-Diaz-del-Castillo, P. E. J. 1083 Schallow, P. 2417 Rivolta, B. 1369 Schauerte, O. 3403 Ro, D. S. 1567 Scheibe, H.-J. 1001 Roder, O. 69, 1839, 2753, 2875 Schick, A. 1911 Roesner, H. 1791 Schille, J.-P. 1397 Rosenberg, Y. 3299 Schillinger, W. 2385 Rosenberger, A. H. 1887 Schimansky, F. P. 2401 Rosier, J. 839 Schmitt, C. 3277 Roth-Fagaraseanu, D. 2425, 2899 Schneider, S. 411 Ruckert, G. 721 Scholtes, B. 1059 Rugg, D. 1767, 2727, 2837 Scholz, H. 205 Rumyantsev, Y. S. 1053 Scholz, M. 3051, 3059 Russell, M. J. 785, 2867 Schroeder, J. 1941 Russo, P. 329, 1631 Schroers, S. 1361 Russo, P. A. 1543 Schüller, E. 463 Rychly, J. 3339 Schutz, R. W. 2099, 2935, 2951 Rylska, D. 905 Schwilling, B. 3237 Rylski, A. 905 Searles, T. 1413 Sefrin, C. 2689 S Segtrop, K. 3011 Saidi, A. 277 Semiatin, S. L. 197, 313, 1227, 1243, Saito, T. 399, 1331, 1519, 1527 1259, 1299, 1307, 1429 Sakai, T. 1331 Senemmar, A. 1723 Sakakibara, A. 1511 Senkov, O. N. 1353 Sakuma, T. 1527 Seno, Y. 1527 Sakuno, F. 699 Sequeira Tavares, S. 3149 Salem, A. A. 1429 Seserko, P. 3011 Salishchev, G. A. 297, 313, 349, 569 Setoudeh, N. 277 San Juan, J. 2393 Seyfert, U. T. 3315 Sarrazin-Baudoux, C. 1995 Sgobba, S. 3149 Sarteaux, J. P. 1599 Sha, W. 1131 Sartowska, B. 891 Shamblen, C. 2737 Satake, T. 1903 Shell, E. 1707 Sathish, S. 1039, 1753, 1799 Shell, E. B. 1941 Sato, H. 635 Shen, J. 2041 Satoh, K. 737 Shevchenko, S. V. 1307 Sauer, C. 1871 Shibanov, A. S. 2285 Sauerbrey, R. K. 979 Shigematsu, I. 343 LX Author Index

Shiina, T. 1775 Sugiura, Y. 1163, 2051 Shim, H.-M. 3229 Sumiyoshi, H. 1745 Shimizu, H. 3117 Sunderkötter, C. 611 Shimizu, M. 941, 1025 Sung, S. Y. 2233, 2265 Shimizu, T. 761 Sung, S.-Y. 447, 3067 Shimodaira, E. 993, 3361 Suzuki, A. 1583, 3133, 3181, 3189, 3269 Shinoda, T. 2271 Suzuki, K. 2115, 3323 Shulov, V. 2777 Suzuki, N. 1519 Shur, C. C. 793 Suzuki, R. O. 245 Sibum, H. 611, 777, 3419 Suzuki, T. 3075 Siemers, C. 839 Swale, W. 581 Sieniawski, J. 371, 597, 971, 1505 Sweet, S. 385 Silva, G. 1369 Szkliniarz, W. 2217, 2225, 2347 Simao, J. 2185 Simões, F 2193 T Skeldon, P. 891 Takagaki, M. 1025 Skotnikova, M. A. 831, 2991 Takahashi, K. 1107, 3117 Skrotzki, B. 3043 Takarev, V 3369 Slyvinsky, A. A. 659 Takashima, K. 1933, 1973 Smith, L. S. 2091 Takeda, J. 1683 Smith, T. 1283 Takeda, Y. 699 Smolin, A. P. 393 Takemoto, Y. 1511 Sorby, K. 815 Takenaka, T. 221 Spath, N. 1171, 1315 Takeuchi, H. 3075 Sridhar, T. M. 3299 Takeuchi, T. 3269 Stahr, C. C. 1009, 3345 Tal-Gutelmacher, E. 1715, 1737 Stanislawski, J. 891 Tamenari, J. 3117 Staron, P. 2793 Tan, M. J. 589 Steger, R. 3377 Tan, Y. 603 Steuwer, A. 2745 Tanaka, J. 3197 Stich, A. 3393 Tanaka, Z. 1903 Stoephasius, J.-C. 2209 Tang, T. 129 Stoiber, M. 929 Tao, H. 2769 Stolyarov, V. V. 1437 Taylor, K. 1767 Stover, D. 463, 487 Telin, V V. 135 Strämke, S. 935 Teliovich, R. V 1259 Streitenberger, M. 659, 729 Terlinde, G. 81, 1839, 2697, 2891 Strohaecker, T. R. 2539 Ter-Pogosyants, E. 511 Strokina, T. I. 2991 Tetyukhin, V. 111 Strudel, J.-L. 2137 Tetyukhin, V V 577, 2285 Sugano, M. 1903 Texier, G. 1323 Sugimoto, T. 1203 Thibon, I. 957, 1323 Author Index LXI

Thomas, R. 2975, 3051, 3059 Villechaise, P. 1469 Thompson, G. E. 891, 2761 Vinokurov, D. 111 Thull, R. 3277, 3315 Viswanathan, G. B. 1559 Tian, J. 419, 2355 Voice, W. 541, 883, 1477, 1759, 2185, Tiley, J. 1559, 2547 2817, 2829 Tiley, J. S. 1413 Voice, W. E. 675, 2409, 2915 Tockner, J. 2853 Vojtěch, D. 2059 Todd, C. 2067 Völkl, R. 847 Toji, Y. 1219 vom Wege, F. 2859 Tominaga, T. 3075 von Niessen, K. 3345 Tomota, Y. 2325 Tonda, H. 1933, 1973 W Tonnessen, K. 815 Wagner, F. 1211 Torjusen, J. E. 815 Wagner, K.-P. 213 Toyoda, K. 761 Wagner, L. 1017, 1823, 2425 Travin, V. V. 2967 Wakashima, K. 1139, 3385 Trindade, B. 2193 Wallis, I. 651 Trygub, M. P. 213, 667 Wallis, I. C. 471, 2277 Tsakiris, V. 1651 Walther, E 3237 Tsuzuku, T. 635 Walz, W. 3043, 3403 Tsybulina, I. N. 2991 Wan, X. 2041 Tuo, X. 1863 Wang, K. 3293 Tuppen, S. J. 675 Wang, L. 2745 Wang, Q. J. 1115 U Wang, X. 337 Ubhi, H. S. 2277 Ward-Close, C. M. 27 Uchino, T. 2309 Watanabe, Y. 993 Udomphol, T. 2829 Watazu, A. 343 Ueda, M. 1583 Wayte, P. 2737 Uhlmann, E. 2293 Wedell, W 2577 Ulrich, T. J. 1421 Wei, H. R. 2449 Ushkov, S. S. 557, 831 Wei, S. 379 Weisenburger, A. 2777 V Weller, M. 2401 Valiakhmetov, O. R. 297, 313, 569 Welter, E 173, 329 Valiev, R. Z. 1437 Wendler, B. G. 905 Van-der-Zwaag, S. 1083 Wenman, M. 2829 Vannes, A. B. 913 Wentzel, C. M. 619, 799 Vaquero, M. 3111 Werner, Z. 891 Vassel, A. 2471, 2609 Westman, E.-L. 1461 Vecino, A. 987 Whittaker, M. T. 1759 Venkatesh, V. 321, 2943 Wikman, B. 1461 LXII Author Index

Williams, J. C. 95 Yang, G. J. 1551, 1731, 2027 Williams, R. 1559 Yang, H. 643, 1195, 1639 Williams, S. 2003 Yang, H. Y. 1405, 1645 Wilson, A. 1283, 1477 Yang, L. 1731 Wilson, A. F. 149, 321 Yang, R. 1115, 1925, 2169, 2177, 2241, Winderlich, B. 949 3189, 3245 Windler, M. 3377 Yang, S. J. 2161 Winter, S. 3315 Yang, Y. 643 Wisbey, A. 471, 2277 Yang, Y. Q. 2479 Wissenbach, K. 525 Yao, Z. K. 603, 715 Withers, P. J. 1045, 2745, 2801 Yashiki, T. 3019, 3103 Witulski, T. 1839, 2697, 2891 Yatsenko, A. P. 135 Wood, J. R. 1, 181, 3035 Ye, W 1863 Woodfield, A. 2737 Yeon, Y. M. 793 Woodward, C. 1045, 2801 Yoshikawa, E. 3103 Wortberg, D. B. 3411 Yoshimura, T. 2769 Wronski, J. 3051 Yu, H. Q. 1623 Wu, H. 365, 2809, 2825, 3083 Yu, K. 173, 2999 Wu, M. H. 1535, 1543 Yu, K. O. 1299 Wu, W. T. 2177 Yu, O. 329 Wu, X. 541, 1067, 1477 Yu, Y. H. 1987 Wu, Y. J. 479, 517 Yu, Z. 3293 Wynne, B. R 1243 Yu, Z. T. 1815 Yuri, T. 1745 X Xia, J. 2433 Z Xiang, H. F. 2241 Zahari, N. I. 1903 Xiao, S. 419 Zaitsev, A. V. 577 Xu, D. S. 2177 Zakaria, M. 1477 Xu, Z. 899 Zalisz, Z. 1699 Zamkov, V. N. 659, 1259 Y Zander, D. 2075 Yamada, A. 1519 Zehetbauer, M. 1445 Yamada, T. 3361 Zeipper, L. 1437, 1445 Yamaguchi, M. 2361 Zeng, L. Y. 2517, 2609 Yamamoto, N. 1235 Zeng, W D. 1623, 1987, 2449, 2569 Yamamoto, Y. 3019, 3103 Zhadkevich, M. L. 229 Yamashita, Y. 737, 3075 Zhang, G. 121 Yamazaki, Y. 2585 Zhang, J. 1823 Yan, Y. L. 425 Zhang, M. L. 715 Yanagisawa, K. 3103 Zhang, P. 1639 Yang, G. 1493 Zhang, P. S. 2609 Author Index LXIII

Zhang, S. Z. 1115 Zhou, T. 1535 Zhang, T. 1551 Zhou, Y. B. 425 Zhang, Z. 337 Zhou, Y. G. 1623, 1987, 2449, 2569 Zhang, Z. X. 921 Zhou, Y. L. 3189 Zhao, B. 643 Zhu, J. 343 Zhao, X. Y. 603 Zhu, K. Y. 365, 2809, 2825, 3083 Zhao, Y. 1639 Zhu, M. 861 Zhao, Y. Q. 165, 365, 1405, 1591, 1645, Zhu, P. 379 2027, 2449, 2517, 2609, 2809, 2825, Zhu, X. 589 3083 Zhu, Y. 2479 Zheng, X. 683, 1831 Zhu, Z. S. 1339, 1645 Zherebtsov, S. V. 313 Zhuk, H. V 667 Zhou, H. 899 Ziaja, W 371, 1505 Zhou, L. 59, 165, 479, 517, 899, 1575, Zubarev, Y. M. 2991 1591, 1815, 2449, 2609, 3293 Subject Index

A Al content 1583

A380 airplane 2659, 2667, 2697 Al Kα imaging 2201 Abrasive wear 1699 Alloy C 1361, 1723 Accident statistics 2727 Alloy development 1067, 1499, 1591, Acid leaching 261 3027 Acoustic emission 2301 Alloying element distribution 2991 Acoustic techniques 1753, 2271 Alloying element effects (Fe and 0) 1099

Activation energy 365, 1163, 2027, 2051, A1203 2517 2393, 2417, 2449 Aluminothermic reduction 2209 Activator material 2523 Amorphous TiAl 2309

Activity coefficient 189 Anatase type TiO2 277 Aero-engine materials 2727, 2845, 2853 Anatase/rutile transformation 277 Aero-engine parts 525, 2793, 2867 Anisotropy 611, 1615, 1871, 2967 Aero-engine technology 2727 Annealing 1863 Aero-engines 2727, 2845, 2883, 2915 Anodic oxidation 1965, 2041 Aerospace applications 49, 95 Anodic repassivation 2099 Aerospace components 2673 Anodization 979, 987 Aging 823, 1147, 1227, 1863, 1925, 2369, Apatite coating 3293 2809, 3035, 3043, 3141, 3173, 3189 Applications of TiAl alloys 2123 Aging response 357, 1067, 1163, 1583, Arc melting process 1299 1591 Arc stability 761 Aging temperature 1511 Arc welding 651, 721, 761 Aging treatment 1551, 1567, 1607, 1855 Architecture applications 27, 49, 95, 2999, Air system 2659, 2689 3103, 3111, 3117 Aircraft applications 2713 Armor applications 173, 3027, 3125 Aircraft seat tracks 329 Armstrong process 479 Airframe applications 2615 Arrhenius plot 1361, 2051 α case 581, 589, 2051, 2495, 3261 Artificial saliva 3229 α layers at ß grain boundaries 1855, 1871 Artillery 2999 α phase formation 1155 Attrition milling 269 α precipitation 1551, 1583, 1651 Autogeneous keyhole welding 699 α titanium single crystals 1973 Automotive applications 39, 95, 3011,

α2 precipitation 1925 3019, 3027, 3035, 3051, 3067, 3075, α2 stabilizers 2331 3393, 3403, 3411, 3419 α‘ martensite 1543 Automotive springs 69, 3035, 3043 α“ martensite 1139, 1511, 1543 Automotive valves 399, 1067, 3011, 3075, a+ß alloys 1389, 3089 3411 a+ß forgings 285 a+ß processing 297 LXVI Subject Index

B Blisks 69, 2785 B2 phase 2153, 2169 Blooms 181 Ball milling 277, 2201 Bode phase diagram 2075 Ballistic evaluation 3125 Boeing 777 airplane 2643 Ballistic impact 2761 Bondability 1031 Ballistic performance 1453 Bonding 807 Bar material 1863 Bonding strength 745 Bar production 337 Bone cement 3307 Basal texture 569 Boride clusters 2339 β alloys 1067, 1535, 1543, 1551, 1583, Boron modifiers 2347 2643, 3035, 3173, 3181, 3189, 3245, Brazed joints 2277 3269 Brazing 769, 2983 β annealing 1715 Brazing filler 769 β forging 69, 285, 1839, 2697 BT 20 419 β grain shape 1871 Bulge test 1499 β grain size 1235, 2829 Burgers orientation 957 βphase 2325 Burn resistance 2809, 2817, 2825, β processed material 1871 2829, 2915 β transus temperature 1251 BuRTi 1067, 2817, 2829, 2915 Bauschinger effect 1243, 1437 Business drivers 2727 Beta C 385, 1017, 1179, 1567, 3035 Butt joints 675 Beta-CEZ 1091, 1345, 1599, 1659 Beta 21S 69, 581, 619, 799, 1131, 1339, C 1361, 1691, 1723, 1737, 1855, 1863 C addition 453, 1067

Bi-lamellar heat treatment 3213 CaF2 slag 205 Bi-lamellar microstructure 431 Ca reduction 245, 261 Bimodal microstructure 1639 Calcium phosphate 3285, 3323 Biaxial creep 2033 Calcium phosphate coatings 3345 Biaxial fatigue 1807 Calculation of properties (JMatPro)1397 Billet manufacture 321 Calometry 2193 Billet processing 297 Carbide debonding 2817 Billets 141, 305, 313 Carbide fracture 2817 Binder 447 Carbide precipitation 1115 Bioactive coatings 3331 Carbide size 2829 Bioactive surface 162 Carbon modifiers 2347 Biocompatibility 1535, 3165, 3181, 3221, Carbon steel 1040, 745 3323, 3361 Carbo-thermic reduction 269 Biomaterials 69, 1139, 1543, 3157 Carburizing 899 Biomechanical behavior 3253 Cast hip stems 3213 Blended elemental (BE) method 399, 495 Cast slabs 173, 181 503 Casting defects 2635 Blended powders 2495 Casting factor 2681 Subject Index LXVII

Casting industry in China 425 Cold working 1519, 1527, 1543, 3089 Casting process 431 Combustion reaction 2511 Casting technology 419, 2681 Component design 2967 Casting texture 2317 Component fabrication 1 Castings 81, 419, 425, 439, 447, 455, Composition control 189 2233, 2615, 2635, 2681 Composition measurement 189 CCT diagram 1397 Compositionally graded material 533 Cell reaction 3277 Compound layer 941 Cell culturing 3285 Compression 1461 Ceramic coatings 3361 Compressive residual stresses 2817 Ceramic crucible 2225 Compressor blades 69, 2769, 2777, Ceramic inclusions 455 2859, 2899 CermeTi 2531 Compressor disk 2853 Centrifugal casting 419, 3011, 3067 Compressor material 552 Centrifugally cast components 2241 Concentrated energy beams 875 Charge density wave 1179 Connecting rods 3051 Charpy impact test 729, 737, 2829 Constitution models 1461, 2301 Chemical inhomogeneities 165 Construction materials 39 Chemistry prediction 149 Consumer goods 39, 95, 2999 Chinese alloys 59, 365 Consumption 59 Chip formation 815, 831, 839, 2293 Contact stress 1691 Chlorination 121, 141 Continuous cast ingots 173 Chlorination technology 129 Continuous casting 285 Civil engineering 39 Conversion of ingots 111 Cladding 745, 753, 799, 2923 Coolant pressure (machining) 815 Cleaning 3111 Cooling rate 1879, 2325 Cleavage fracture 2829 Corrosion 2041, 2099, 2777, 2983 Cleavage type failure 1987 Corrosion behavior 3205, 3221, 3229, Closed die forging 81, 549 3307, 3339, 3361

CO2 laser 2651 Corrosion fatigue crack growth 2083 Coated crucible 2217 Corrosion fatigue strength 3237 Coated fiber technique 57 Corrosion protection 745, 2107 Coating bath temperature 3299 Corrosion resistance 769, 891, 2075 Coating technology 867 Corrugation machine 2627 Coatings 69, 875, 1009, 2041, 2193, 2441, Cost 2727, 2999 2455, 3323 Cost analysis 479 Cogging process 285 Cost effective production 1067, 2503 Cold formability 3019, 3097 Cost of steam generators 13 Cold forming 3141 Cost reduction 419, 503, 2999, 3393 Cold hearth melting 81, 2737 Covering gases 2651 Cold rolling 285 Cold workability 3019, 3097 LXVIII Subject Index

CP-Ti 343, 349, 439, 447, 479, 611, 627, Cyclic deformation behavior 1723, 3237, 699, 745, 769, 793, 913, 941, 1031, 3385 1099, 1203, 1211, 1429, 1437, 1445, Cyclic deformation curves 2417 1919, 1933, 2033, 2107, 2689, 2959, Cyclic oxidation 2277, 2441, 2449, 2455, 2983, 3111, 3117, 3197, 3403 2471 CP-Ti matrix composites 2563 Cyclic stress intensity factor 1919 CP-Ti + Pd 2099 Cyclic stress-strain curves 1807 CP-Ti + Ru 2099 Cr addition in TiAl 2325 D Crack closure 1911, 1995, 2003 Damage evolution 1791, 1903 Crack coalescence 1911 Damage tolerance 2667 Crack growth retardation 1979 DAT 55G 3133 Crack nucleation 1377,1675,1745,1775, Deep case hardening 867 1783, 1831, 1855, 1871, 1887, 1895, Deep drawing 611, 619, 627, 643, 3403 1903, 1911, 1949, 2761, 2959 Deep forming 3403 Crack nucleation sites 2777, 2883 Deep hardening 867 Crack path 1933 Deep rolling 1017, 1059 Crack profile 1919, 1979 Deep water casing 2967 Crack propagation 1957, 1973 Defects 2899 Creep 1623, 2019, 2027, 2033, 2137, DEFORM 2793 2161, 2393 Deformability 3083 Creep crack growth 1831 Deformation 1203, 1453 Creep fatigue interaction 2003 Deformation behavior 1831 Creep feed grinding 2817 Deformation mechanisms 1493, 2249 Creep flattening 181 Deformation mode 1251 Creep forming 635 Deformation stress 393 Creep properties 1499, 1831, 1839, 1863, Degradation of crucible coatings 2217 2011 Delamination 2455 Creep resistance 399, 2753 Dendrites 949, 971 Creep strength 1855, 2875, 2915 Densification 495 Crevice corrosion 2099 Density 411 Crushing 141 Density of states 2177 Cryogenic applications 3149, 3197 Dental casting 3261, 3269 Cryogenic temperature 1485, 1493 Design optimization 2727 Crystal orientation 1973 Detactibility 455 Crystal plasticity 1283 Diffraction analysis 1107 CT 20 1493 Diffraction pattern 1179 Cutting 831 Diffraction streaks 1179 Cutting conditions 839 Diffusion 1091 Cutting speed 2185, 2293 Diffusion bonding 49, 569, 651, 675, Cutting tool 815 683, 691, 2539, 2673 Diffusion hardening 921 Subject Index LXIX

Diffusion mechanism 1083 E Diffusion zone 929 EBCHM 181, 197 Dilatometry 495, 1369 EBSD 1211, 1283, 1291, 1299, 1315, Direct rolling 181, 285 1339,1345,1469,1759,2145 Directional solidification 2361 Elastic constants 1421 Discoloration 3103, 3117 Electric machines 2975 Disk manufacturing 2883 Electrical discharge grinding 883 Dislocation arrangement 1815, 1987 Electrical resistivity 1163, 1203 Dislocation density 1799 Electro deoxidation process (EDO) 27, Dislocation pile-ups 2011 245, 479 Dislocation structure 1477 Electro discharge machining (EDM)2883 Dislocations 1267 Electrochemical charging 1361 Dispersion strengthening 229 Electrochemical drilling 847 Dissimilar material joints 793 Electrodeposition 3299, 3323 Dissimilar pairings 675 Electrolyte 855 Double T-butts 777 Electrolyte concentration 979 Dovetail 2769 Electrolytic cell 237 Drawability 1377 Electrolytic coatings 875 Drawing load 357 Electromagnetic levitation 411 Drawing tool material 3403 Electropolishing 855, 861 Drill pipes 2935 Electrowinning 221, 237 Drilling 847 Electron beam furnace 667 Drilling system 2999 Electron beam glazing 213 Droplet transfer 761 Electron beam melting 1259 DTA 495 Electron beam surface treatment 2777 Dual alloy welding 715 Electron beam welding 707, 715, 2875 Ductile/brittle transition 2257, 2417 Electron probe microanalysis 2051 Ductile fracture 2829 Electronic condition 1519 Ductility 2331 Elemental powder metallurgy 2201 Duplex aging 1651 Embrittlement 1731 Duplex annealing 1715 Emerging applications 2999 Duplex microstructure 1823, 2377 Emerging markets 1 Dwell fatigue 2091 Emerging technologies 81 Dwell time 1987 Engine disk 2891 Dynamic compression 2377 Engine prize 2845 Dynamic loading 1453 Engine pylon 2659 Dynamic recovery 365 Engine valves399, 1067, 3011, 3075,3411 Dynamic recrystallization 365, 1187, Environment assisted cracking 651 1219, 1267, 2317, 2417 Environmental effects 1775, 1949, 1995, Dynamic spheroidization 1243 2003 Equal channel angular pressing 285, 343, 1437, 1445 LXX Subject Index

Equiaxed microstructure 1831 Fatigue strength (cont) Equivalent stress 2959 - IMI 834 welds 2753 Erosion test 1001 - KS EL-F 3089 ESR 205, 221, 229, 2209 - LCB 385, 3043 ESR furnace 205 - MMCs 399, 2593, 2601, 2907 Eutectoid alloys 229 - SP-700 385, 1847 Evaporation of alloying elements 197 - Surface treatment 823, 941, 1001, 1 Evaporation rate 189 1017, 1025, 1053 Exhaust manufacture 619 - Ti-1100 2425 Exhaust nozzle link 2463 - Ti-6242 1823 Exhaust systems 69, 3019, 3403 - Ti-6242 welds 2753 Explosive cladding 285 - Ti-6246 1871, 2891 Explosive foil cladding 799 - Ti-6246 welds 2875 Explosive forming 619 - Ti-811 3059 Explosive welding 799, 807 - Ti-10-2-3 1895, 3059 Extraction metallurgy 1, 27, 81 - TiAl based alloys 2241, 2409, 2425 Extrusion 329, 2317, 2829, 2899 - Ti-3Al-2V 3059 - Ti-5Al-2.5Sn ELI 1745 F - Ti-6Al-7Nb 337 F/A-22 455, 1631, 2635 - Ti-6Al-4V 181, 431, 495, 1039, 1753, Fabrication 59, 81 1759,1767,1775,1783,2681,2761, Fabrication methods 2615 2883, 3059, 3075, 3213 Face milling 823 - Ti-2.5Cu 3059 Failure mechanism 1887 - Ti-29Nb-13Ta-4.6Zr 3181 Fasteners 13 - VT 6 2777 Fastening techniques 777 - VT 8M 2777 Fatigue behavior 1059, 1807, 1815, 1911, - VT 16 385 2091 Fatigue testing 651 Fatigue-corrosion interaction 1995 Fe distribution 737 Fatigue crack propagation 707, 729, Feathery microstructure 2325 1759, 1847, 1879, 1895, 1925, 1933, FFC Cambridge process 27, 245, 479 1965, 1979, 1995, 2003, 2681, Fiber reinforced composites 2487, 2569, 2697, 2837, 2975 2577, 2585, 2593, 2907 Fatigue damage 1753, 1791, 1799 Fiber processing route 2503 Fatigue life prediction 1887 Filament composites 2487 Fatigue strength Filler metals 2983 - ß forged Ti-6A1-4V 2697 Filler wire 737 - Beta C 385 Filters 13 - Beta 21S 1855, 1863 Fine grain processing 343 - BuRTi 2915 Fine grained billet 297 - CP-Ti welds 2959 Fine grained material 343, 349 - IMI 550 3059 Subject Index LXXI

Fine particle bombardment 993, 1025, Fretting 1667 3361 Fretting fatigue 1039, 1675, 1683, 1707, Finite element analysis 1267, 1283, 1461, 2769 1485, 1505, 2569, 2593, 2769, 3253 Friction 2433 Finite element analysis of fretting fatigue Friction coefficient 557, 611, 905, 1707 2769 Friction properties 935 Finite element simulation of forming Friction stir welding 49, 785, 2867 2673, 2689 Friction welding 793, 2265, 2271, 2867 Finite volume method 753 Frictional wear 1683 Fishing industrie 13 Fuzzy logic modelling 1413 Flap tracks 2659 Flat bottom hole 297 G Flow stress 589, 597, 603, 635, 1267, Gamma stabilizers 2331 3089 Gamma-TAB 683 Fluoride electrolyte 237 Gadolinium modifiers 2347 Fluoride electrowinning 237 Gas atmosphere 929, 949 Foils 349 Gas atomization 503 Force-locking fasteners 777 Gigacycle fatigue 1775, 1783 Foreign object damage (FOD)2409, 2761 Glow discharge emission spectroscopy Forge 2 modelling 357 (GDOES) 2719 Forging 285, 305, 313, 321, 569, 597, Glow discharge plasma 905 1315, 1377, 2123, 2257, 2285, 2309, Golf club heads 3133, 3141 2643, 2659, 2713, 2793, 2829, 2853, Graded materials 1919, 1957, 1965 2859, 2891, 2943 Grain boundaries 2145 Forging parameters 2859, 2891 Grain boundary α 1659, 2809 Forging technique 2859 Grain boundary misorientation 1339 Formability 619 Grain boundary mobility 1307 Forming limit 611 Grain boundary segregation 2355 Forming limiting curves 3403 Grain boundary sliding 2249 Forming temperature 581 Grain growth 569, 603, 1307 Fractography 2837 Grain size1437, 1767, 1783, 1911, 1919, Fracture mechanisms 1453, 2563, 2829 2019, 2153, 2249, 2331, 2809 Fracture mode 1731 Grain structure 329, 1267 Fracture morphology 1615, 1895, 2417 Grinding 2185, 2817 Fracture strength 2753 Growth kinetics of precipitates 1083 Fracture surface 831, 1067, 1477, 1745, Gum metal 399, 1519, 1527 1979, 2777, 2829, 3269 Fracture surface roughness 1895, 1957 H Fracture toughness 181, 337, 651, 707, Haemocompatibility 3315 729, 1575, 1615, 1623, 1645, 1659, Hall-Petch relation 2355 1839, 1847, 1871, 1925, 1957, 2643, Hard α inclusions 2635, 2737 2713, 2829, 2891 Hardenability 1575 Frequency effects 1995 LXXII Subject Index

Hardness 1009, 1039, 1147, 1737, 2271, Hot forming 635 2983, 3173 Hot plasticity 371 Hardness distribution 793 Hot rolling 285, 2153 Hardness profile 941, 2233, 2265, 2719 Hot seizing 635 Hardness values 357, 2753 Hot workability 3097 HDH powder 1235 Hot working 2317, 3089 Hearth melting process 189 Hunter sponge fines 1235 Heat affected zone 659 Hybrid TiAl panel 2627 Heat exchangers 13, 2983 Hybrid surface modification 1025 Heat impact 659 Hydride-dehydride (HDH) process 479, Heat resistance 3019 487, 503, 1353 Heat tinting 1659 Hydride precipitates 1203 Heat treatment 1345, 1499, 1535, 1559, Hydrides 1731 1575, 1591, 1615, 1639, 1645, 1683, Hydroforming 69, 2689 1767, 1879, 2393, 2793, 2809 Hydrogenation 511 High density inclusions 2737 Hydrogen absorption 2099 High frequency inductive press-welding Hydrogen absorption/desorption 1715 69, 2753 Hydrogen diffusion 1361 High pressure torsion 1437 Hydrogen effects 1723, 1731, 1737 High rate deformation 603 Hydrogen embrittlement 1361, 1949 High speed machining 49, 823 Hydrogen pump 3197 High speed milling 2185, 2817 Hydroxyapatite 3299, 3361 High speed motor rotors 2975 High temperature alloys 229 I High temperature compression tests 365 Ilmenite 121, 129, 269 High temperature deformation behavior Ilmenite upgrading process 129 365 IMI 550 675, 1477, 1807, 2745 High temperature fatigue 1815, 1987 IMI 685 2853 High temperature fatigue crack propaga- IMI 834 189, 1291, 1949, 1995, 2609, tion 1995, 2003 2753, 2837, 2845 High temperature flow stress 297, 357, 371 IMI 834 + 1Nd 1499 High temperature fracture strain 371 IMI 834 matrix composites 2569, 2593 High temperature properties 229, 399, Immersion test 891 569, 643, 1831, 2915 Impact energy 707, 1591 High temperature S-N curves 297, 365 Impedance spectroscopy 3339 Hole making 2883 Induction heating 875 Homogenization 495 Induction scull melting 2339, 2355 Honeycomb structures 69, 2627 Industrial scale 2285 Hot deformation 379, 1219 Inertia welding 2875 Hot die forging 715 Infiltration 2523 Hot extrusion 285, 2123 Ingot chemistry 197 Hot formability 643 Ingot forging 141 Subject Index LXXIII

Ingot metallurgy 471 L Ingot processing 305 Lamellar microstructure 1639, 1659, 1831 Ingot production 13, 2899 Landing gear 2463, 2643, 2659 Ingot quality 2899 Large scale billets 313 Ingot shrinkage 157 Laser additive manufacturing 503, 2615 Ingot surface defects 213 Laser beam cutting 5 Insert layer 745 Laser beam welding 2651, 2689 In-situ deformation 1949 Laser cladding 2785 In-situ tensile tests 1469 Laser deposition 533, 541, 549, 1389, Inspection 285 2547 Intense pulsed electron beam 2777 Laser fabricated materials 541 Interface energy 1211 Laser gas alloying 1001 Interface fracture 2569 Laser manufacturing 525 Interface reaction 745, 2479 Laser marking 3377 Interface stability 799 Laser melting 525 Interface structure 807 Laser nitriding 949 Interference microscopy 1941 Laser shock peening 1045, 2801 Intergranular cracking 2825 Laser surface alloying 971 Intergranular sliding 603 Laser surface remelting 2169 Interior crack nucleation 1775, 1783 Laser treatment 847, 913, 971, 3369 Intermetallic particles 1075 Laser welding 2975 Internal friction 2393, 2401 Lattice defects 1203 Internal nitriding 957 Lattice distortion 1737 Intramedullary nailing 3253 Lattice parameters 3323 Inverse pole figures 1315 LCB alloy 357, 385, 1017, 1155, 1227, Isothermal aging 1163 1323, 1911, 3043, 3369 Isothermal forging 285, 1187, 2285, 2899 LCF 1623, 1753, 1839, 1949, 1987, 2417, 2585, 2853 J Life cycle costs 2845 Joinability 659 Life prediction 1887, 2585 Joining 27, 557, 651, 667, 777, 785, 2265, Linear friction welding 2745, 2867 2271 Linear friction welding machine 69, 2867 Joining methods 2615 Linear mechanical joining 777 Joint strength 769 Lining of foils 1031 Liquid fiber coating 2487 K Liquid pool depth 157 Kinetics of evaporation 197 Liquid titanium 411 Kirkendall voids 2455 Low cost alloys 3083 Kitagawa diagram 1895 Low cost manufacturing 3403 Kroll process 141 Low cost melting 3323 KS EL-F 3089 Low cost powder 517 KS Ti-9 3097 Low cost production 3419 Low cost shell material 419 LXXIV Subject Index

Low cost TiAl 2209 Melting process control 81 Low modulus 3157 Melting rate 197 Low temperature annealing 3353 Melting technologies 81, 229 Low temperature fracture mechanisms Metal hydride reduction 479 2829 Metal injection molding 463 Lubricants 1009, 3403 Metal-mold reaction 439, 2233 Metal powder 253 M Metal working processes 81 Machinability 3027 Metallothermic reaction 253 Machining 81, 557, 815, 823, 831, 839, Metastable phases 1567 847, 2293, 2793 Metastable structure 1179 Macroscopic segregation 165 Mill product shipment 39 Macrostructure 297, 337, 549, 1259 Micro spot brazing 769 Magnetic field 659 Micro tensile test 683 Magnetic properties 1437 Microanalysis 1115 Magnetically controlled ESR 229 Microcracks 1691, 2761 Manufacturing technologies 27, 111 Microduplex structure 1219 Marine application 95 Microhardness 831, 1369, 2991 Marine corrosion 2923 Microporosity 3353 Marine vessels 2923 Microscopic segregation 165 Martensitic reaction 1099 Microstructural model 1505 Martensitic transformation temperature Microstructure 463, 1099, 1397 - Beta C 385, 1179 Massive phase transformation 2325, 2369 - Beta-CEZ 1345 Master alloys 13, 2225 - Beta 21S 1737, 1855, 1863 Matano interface 1361 - Brazed joints 2277 Material pull-out 2817 - BuRTi 2829 Materials development 27 - CP-Ti 343, 349, 1445, 3403 MCrA1Y coatings on TiA1 2455 - IMI 834 + 1Nd 1499 Mean stress effect 1767 - Laser fabricated 533, 541, 2547 Mechanical alloying 2193 - LCB 357, 385, 1155, 1227, 3043 Mechanical properties 1107, 1259, 1331, - SP-700 385, 1147, 1615 1445, 2975 - TC 11 1623, 1987 Mechanical spectroscopy 2393 - Ti-17 297, 1171, 1839 Medical applications 49, 95, 525, 3165, - Ti 40 2809, 2825 3173, 3181, 3189, 3205, 3213, 3221, - Ti-555 371, 1559 3229, 3237, 3245, 3253, 3261, 3269, - Ti-6-22-22 337, 1631, 1639, 1645 3277, 3285, 3293, 3299, 3307, 3315, - Ti-6242 1667, 1823, 1831 3331, 3339, 3345, 3353, 3369, 3385 - Ti-6246 1839, 1871, 1879, 2891 Melt contamination 2217 - Ti-10-2-3 603, 1187, 1219, 1895 Melt spraying 667 - Ti-15-3 541, 1179, 1227, 1331, 1607 Melting 1, 111, 141, 149, 189, 205, 221 Subject Index LXXV

Microstructure (cont) Modelling (cont) - TiAl based alloys 1067, 2123, 2339, - Forging 313, 1377 2369, 2393, 2401 - Forming 2673, 2689

- Ti2AlNb based alloys 2161 - Fretting fatigue 1675, 2769 - Ti-Al-V alloys 1389 - Heat transfer 2169 - Ti-4.5Al-5Mo-1.5Cr 643 - High temperature deformation 1461 - Ti-5Al-1Sn-lZr-1V-0.8Mo 651 - Hot deformation 393 - Ti-5Al-2.5Sn ELI 3149 - Implant fracture 3253 - Ti-6Al-4Fe-(0.1-1.0)Si 1123 - Interface reactions 439 - Ti-6Al-4.8Sn-2Zr-lMo-0.4Si-lNd 1115 - Melting 81, 197 1925 - Microstructural evolution 321, 1267, - Ti-6Al-4V 173, 181, 305, 313, 321, 371 1461 541, 569, 597, 1243, 1259, 1267, 1453 - MMCs 2569, 2593 1707, 1767, 1979, 3213 - Properties 1397, 1405 - Ti-6Al-4V ELI 699 - Rupture 1485 - Ti-24Al-17Nb-0.5Mo (at%) 2169 - Stress distribution 1505 - Ti-48Al-2Cr-2Nb (at%) 2347 - Tensile properties 1413 - Ti-B19 1195 - Texture 1283, 1377, 2385 - Ti-(1.5-2.2)Fe-O-N 1107 - Transformation kinetics 1091, 1131 - Ti-Nb-Al alloys 1139 - VAR 149, 157 Microstructure/property relationship 1389 - Welding 753 Microtexture 1291, 1339, 1823 - Wear 1667 Military vehicles 2999 - Wiredrawing 357 Milling 2817 Modulus of elasticity 1421, 1519, 1527, MMC aerospace applications 69 1543,1551,1651,3157, 3189 MMC fabrication 2907 Mold material 439, 447, 2233 MMC interface 2563 Mold reactions 419, 439, 447 MMC processing 1353 Molten salt electrolysis 253 MMC properties 2907 Monte Carlo simulation 1307 MMCs 399, 2463, 2471, 2479, 2487, 2495, Morphology of oxides 2449 2503, 2511, 2517, 2523, 2531, 2539, Motorcycles 39, 3075 2547, 2555, 2563, 2569, 2577, 2585, Multi-oriented columnar TiAl 2361 2593, 2601, 2609, 2907 Multicomponent growth 1083 Mo concentration 957 Multiphase microstructures 2137 Mo equivalent 1535 Multiple forging 569 Modelling Multiple-pass overlay welding 699 - Component design 2967 Multizone ultrasonic inspection 285 - Corrosion fatigue crack propagation 1995 - Crack propagation 1965, 1973 N - Crystal plasticity 1315 Nanocrystalline CP-Ti 1445 - Deformation 2301 Nanocrystalline TiAl 2309 - EB glazing 213 Nanoindentation 2067, 2433 LXXVI Subject Index

Nanostructured layers 1059 0 Nanostructured Ti-Si intermetallics 2193 Oblique joints 675 Nb-rich TiAl alloys 2369, 2385, 2401 Ocean civil engineering structures 2923 Nd additions 1499 Offshore applications 2935, 2943, 2951 NDI techniques 2635 Offshore drilling 2935 Near ß forging 285, 1623 Offshore materials 2935, 2943 Near net shape forging 2697, 2899 Offshore production 2999 Near net shape processes 503 Omega phase 1139, 1195, 1511, 1535, Near net shape processing 1, 1353, 2309 1551, 1583, 1607, 1651 Near surface residual stresses 1059 Open die forging 597 Net shape technology 2233 Optical floating zone melting 2361 Neural networks 1389, 1405, 1413 Ore resources 129 Neutron diffraction 1045, 1345, 2793, Ore resources in CIS 13 2801 Orientation relationships 957, 1075, New applications 39 1291, 1377 New VSMPO alloys 111 Orthopaedic implants 69, 3157 Ni-free shape memory alloys 3385 Orthorhombic phase 2137, 2145, 2153, Ni plating 987 2161, 2177 NiTi 393, 463, 861, 1903, 3221 Osteoprogenitor cells 3331 Nitric acid 3117 Oswald ripening 1075 Nitride coating 627 Oxidation 913, 2041, 2051, 2059, 2067, Nitriding 941, 949, 1369 2241, 2277, 2441, 2449, 2471, 2825 Nitridation behavior 2115 Oxidation barrier 589 Nitrogen content 949, 1001 Oxidation behavior 3103, 3403 Non-contact techniques 411 Oxidation rate coefficient 2449 Non-hydrogen carburizing 899 Oxidation treatment 867 Nondestructive testing 135 Oxide coating 627 Nonlinear acoustic 1799 Oxide formation 1699 Nonlinear elasticity 1527 Oxide layer 979, 3285 Notch tensile strength 1147 Oxide layer thickness 2719 Notches 2425 Oxide scales 2067 Nozzle actuator piston rod 2463 Oxycarbide 121 Nucleation and growth 1091, 1171 Oxygen content 761, 1421, 1519, 1651, Numercial simulation of diffusion 1361 1699, 2209, 2225 Numerical simulation of residual stresses Oxygen content prediction 149 2793 Oxygen diffusion 905 Numerical simulation of transformation Oxygen diffusion zone 2719 kinetics 1171 Oxygen hardening 921 Nyquist diagram 2075 Subject Index LXXVII

P Pocket wave resistance 3103 Pack rolling 3097 Polarization resistance 2107 PAM + extrusion 329 Polarization test 3229 Panels 777 Polishing mechanism 861 Paris law 1965 Polymorphous transformation 277 Partial slip 1675 Pool depth 149 Particle reinforced composites 2531, 2539, Pore size 487 2563, 2601, 2609 Porosity 487, 495, 1009 Partitioning 1115 Porous composite 2511 PFZ 1871 Porous parts production 487, 511 Phase diagrams 357 Porous titanium 3157 Phase field method 1075 Potentiodynamic polarization 2075 Phase relationship 1123 Potentiodynamic resistance 2107 Phase separation 1075 Powder coated fiber 2503 Phase stability 1107 Powder production processes 261, 517 Phase transformation 533, 831, 1091, 1131, Powder siliconizing 2059 1179, 1251, 1275, 1323, 1339, 1369, Power plant applications 49 1511, 1599, 3165 Pre-martensitic phases 1567 Physical properties 1397, 1575, 2177 Pre-oxidation 3293 Physical vapor deposition 1025 Pre-treatment melting process 2517 Pickling 3117 Precipitate morphology 1607 Pin-on-disc tribometer 2433 Precipitate shape 1083 Planar slip 1987, 2011 Precipitation 1123, 1227, 2027 Plasma arc cold hearth melting 2339 Precipitation kinetics 1163 Plasma arc melting 173, 329 Precision casting 431 Plasma arc welding 699 Precision forging 2899 Plasma carburizing 899 Prediction of properties 1397, 1405, 2943 Plasma coating 1707 Preform reduction process 261 Plasma nitriding 929, 935 PREP 503 Plasma quench process 479 Press welding 69, 2753 Plasma sprayed titanium coatings 3307 Pressureless melt infiltration 2523 Plasma spraying 2455, 3345 Primary a volume fraction 1767 Plastic anisotropy 619 Primary processing 27, 81 Plastic deformation 1275, 1469, 3205 Prismatic dislocations 2161 Plastic strain compression 1283 Processing 321, 343, 1067, 1445, 3157 Plate fabrication 181 Processing parameters 683, 861 P/M processing 399, 463, 471, 479, 487, Production of titanium metal 237 495, 503, 511, 517, 525, 1235, 1353, Production statistics 425 1485, 2153, 2495, 2555, 2563, 2601, Production technology 81 2899, 3157 Profilometry 1941 P/M products 13 Projectiles 3125 P/M technology in China 503 Protein adsorption 3345 LXXVIII Subject Index

Pseudo elasticity 1535, 1543 Resistance heating 875 PST crystals 2361 Resistance heating ignition 2201 PT 3V alloy 831 Resistance seam welding 753 Pt group metal additions 2107 Resistivity measurements 1131 Pulse plating 979 Resonant ultrasound spectroscopy 1421 Pulsed plasma beam 891 Resources 59 Pylon 2667 Ribbons 349 Pyrometry 411 Ring rolling 81 Ripple fatigue 2091 Q Risers 2935 Qualification testing 2943 Roller track 69, 2697 Quality improvements 2737 Rolling 349, 1823, 2123, 2385 Quality standards 425 Roofs 39 Quantitative fractography 2837 Rotary forging machine 305 Rotary friction welding 2867 R Rotating components 2737, 2883 R-ratio 1775, 1815, 2003 Roughness of coatings 1009 Radiography 455, 2635 Rutile 121, 129 Rare earth additions 2355 Rutile layer 921 Reaction sintering 2201 Recast surface layer 883 S Recovery 1323, 2011 Safety 2845 Recrystallization 597, 1211, 1227, 1267, Scale 2115 1275, 1323, 1339 Schmid's law 1469 Recrystallization texture 2385 Scrap 205 Reduction by methane gas 121 Scratch test 987 Reduction of costs 3419 SCS-6 fibers 2479, 2487, 2569, 2577, Reduction process 245, 253, 261 2585, 2593 Refining of lamellar structure 2355 Sealing welding 699 Refining reaction 2209 Seam welding 745 RGD peptides 3331 Seawater corrosion 2083 Reliability 2727 Security jacket 69 Remelted surface layer 213 Segregation 165, 1631 Removal speed 855 Self-propagating high temperature synthesis

RE203 2517 2511 Repair of blisks 2785 SEM BS imaging 1187 Repair of compressor blades 2777 Severe plastic deformation 1437, 2067 Residual strains 2793 Shape memory alloys 463, 1139, 1903, Residual stress distribution 1053 3221, 3385 Residual stresses 941, 1039, 1045, 1059, Shear bands 839, 1453, 2761 1599, 2425, 2713, 2745, 2793, 2801, Shear fatigue 2627 2817, 2959, 3377 Shear modulus 1421 Subject Index LXXIX

Shear strain 1331 SP-700 385, 581, 635, 691, 941, 1025, Shear strength 691, 807, 2271, 2983 1147, 1235, 1615, 1683, 1847 Shear strength of joints 2277 SP-700 matrix composites 2585 Shear zone 1691 Spark anodization 979, 3339 Sheet manufacture 577 Specific heat 157 Sheet metal forming 581, 611, 619 Specific modulus of elasticity 2123 Sheet rolling 2257 Specific yield stress 2123 Sheets 349, 577, 2417 SPF 49,569,577,581,589,597,603,635, Shining surface finish 855 691,2659,2673,2689 Short fatigue crack propagation 1911, SPF/DB 49 1919 SPF press 2673 Shot peening 847, 1017, 1031, 1039, 1053, Spheroidization kinetics 1243 2425, 3043 Spin forming 2689 Shrinkage 3269 Split-Hopkinson bar experiment 2377 Si content 1631 Sponge blocks 135 SiC composites 2503 Sponge production 13, 39, 59, 111 SiC fibers 2463, 2471, 2487, 2907 Sponge shipment 39 Silicides 229, 1123, 1631, 1925, 2361, Sporting goods 2999, 3133 2825 Sports equipment 95 Simulation of crack propagation 1973 Springs 69, 3035, 3043 Simulation of rolling process 393 Stamping 557 Simulation of VAR process 149, 157 Statistical analysis of S-N curves 1847 Single crystals 1933, 1973 Statistics of products by shape 39 Single-melt process 173 Statistics of properties 471 Sintering 2563 Steam turbine blades 2991 Skull melting 13 Steel plate 745, 753 Slabs 205 Stents 3221 Slag composition 221 Step-by-step rolling 285, 1639 Slip 1691 Strain hardening 1429, 2011 Slip distribution 1823 Strain path 1243 Slip modes 1469 Strain rate 371, 597, 603, 635, 1187, 1267, SM 1140 fibers 2471 1477, 1599, 1731 Smearing 2817 Strain rate sensitivity 365, 1251, 1461 S-N curves 1745, 1759, 1775, 1783, 1879, Strength/ductility combination 1591 1895, 1903, 2153, 2593, 2681, 2975 Strengthening by chemical compound 13 Soft zones 1659 Stress anomaly 2377 Sol-gel procedure 3277 Stress corrosion cracking 2083 SOLAR 149 Stress distribution 1505, 2801 Solid solution strengthening 229, 3089 Stress enhanced oxidation 2067 Solidification 157, 949, 1299, 1377 Stress exponent 2027 Solution temperature effects 2809 Stress induced martensite 1527, 1567 Stress intensity factor 1941 LXXX Subject Index

Stress joints 2935, 2943, 2951 Sustained load cracking 2091, 2951 Stress ratio effect 1775, 1815, 2003 Sustained load strain 2091 Stress-strain behavior 1429, 1599 Synchroton X-ray diffraction 2745, 2801 Stress-strain curves 357, 1219 Stretch forming 3403 T Striations 2837 TAC-1B 715 Strip drawing test 3403 Taper stress joints 2935, 2943, 2951 Strip production 3097 Tarnishing 3111 Submicrocrystalline structure 313, 349 TC 11 715, 1623, 1987 Submicron grained sheets 569 TEM 1075, 1107, 1123, 1131, 1179, 1195, Substrate 941 1715

Super α2 2479 Temperature dependence of flow stress Super α2 matrix composites 2479 1429, 1461 Super pure titanium (5N grade) 141 Temperature effect on fatigue strength Superplastic roll-forging 285 1745 Superplasticitiy 1219, 1251, 1519, 1527, Tensile properties 2249, 2257, 2309, 2325 - Alloy C 1723 Surface alloying 883, 891, 1001 - β forged Ti-6Al-4V 2697 Surface coating 2041 - Beta C 385, 3035 Surface condition 3111, 3377 - Beta 21S 1723, 1855, 1863 Surface cracking 823 - BuRTi 2829, 2915 Surface damage 2817 - Calculation (JMatPro) 1397 Surface defect density 3353 - CP-Ti 349, 3403 Surface engineering 867 - DAT 55 G 3133 Surface finish 855 - IMI 550 1477, 1807, 3059 Surface glazing 213 - IMI 685 2853 Surface hardening 557, 875, 1699, 3075 - IMI 834 2753 Surface hardness 921, 1017 - IMI 834 + 1Nd 1499 Surface integrity 2817 - KS Ti-9 3097 Surface layer hardness 899 - LCB 385, 3043 Surface melting 2777 - MMCs 399 Surface microhardness 883 - Modelling 1413 Surface modification 3369 - SP-700 385, 1147, 1847 Surface morphology 3117 - Ti-17 1839, 2853 Surface roughness 627, 691, 855, 883, - Ti 40 2809 905,993,1039,1053,1847, 2185,2425, -Ti-1100 2425 2777, 2817 - Ti-555 2643 Surface scaling 921 - Ti-6-22-22 337, 1645 Surface structure 3315, 3369 - Ti-6242 1839 Surface tension 411 - Ti-6246 1839, 1871, 1879, 2785, 2891 Surface topography 2817 - Ti-811 3059 Surface treatment 1017, 1025, 2777 - Ti-10-2-3 1895, 3059 Subject Index LXXXI

Tensile properties (cont) Thermo-hydrogen processing 1353 - Ti-15-3 1331, 1607 Thermo-mechanical fatigue test 2577, 2585 - TiAl based alloys 1067, 2241, 2339, Thermo-mechanical parameters 393 2369, 2425 Thermo-mechanical treatment 321, 337,

- Ti2AlNb based alloys 2137, 2153 549,597,1171,1259,1291,1299,1331, - Ti-Al-V alloys 1389 1575, 1631, 2033, 2123, 2145, 2309, -Ti-1.5Al 3019 2317, 3035 - Ti-3Al-2V 3059 Thermodynamic 1083 - Ti-4.5Al-4V-2Mo-2Fe 1615 Thermoelectric coefficient 135 - Ti-5Al-2.5Fe 495 Thermography 1791 - Ti-5Al-2.5Sn ELI 1745, 3149 Thin gage products 3097 - Ti-6Al-4.8Sn-2Zr-lMo-0.4Si-1Nd 1925 Three-dimensional isothermal forging 313 - Ti-6Al-4V 173, 181, 313, 495, 569, 577, Three-dimensional pressing 1823 1477, 1807, 2853 Ti-17 189, 297, 379, 1171, 1315, 1377, - Ti-B19 1575 1599, 1839, 2853 - Ti-B20 1591 Ti-26 1405 - Ti-Cr-Cu alloys 3261 Ti 40 2809, 2825 - Ti-2.5Cu 3059 Ti 600 2027 - Ti-(1.5-2.2)Fe-O-N 1107 Ti-1100 1017, 1965, 2425, 2609 - Ti-29Nb-13Ta-4.6Zr 3181, 3189, 3269 Ti-1100 + 0.1Y 2027 - Ti-35Nb-7Zr-5Ta 1651 Ti-555 371, 1559, 2643 - Ti-20V-4Al-1Sn 3141 Ti-6-22-22 337, 1631, 1639, 1645 - VT 16 385 Ti-6242 379, 683, 799, 1017, 1131, 1823, - Welds 715, 721, 2753, 2875 1831, 1839, 1957, 2011, 2067, 2753, Tension-compression anomaly 2967 2845 Ternary element effects on TiAl 2331 Ti-6242 matrix composites 2339, 2471, Texture 297, 349, 1211, 1259, 1275, 1283, 2487, 2593 1299, 1307, 1315, 1323, 1331, 1339, Ti-6242/γ-TiAl diffusion bonding 683 1345, 1377, 1429, 1759, 1807, 1823, Ti-6246 1839, 1871, 1879, 1887, 1995, 2033, 2385, 2401, 3385 2003, 2785, 2845, 2875, 2891 Thermal barrier coatings 2441 Ti-662 matrix composites 2531 Thermal conductivity 157 Ti-811 1131 Thermal desorption spectroscopy 1715 Ti-10-2-3 471, 603, 987, 1017, 1163, 1187, Thermal expansion coefficient 1369 1219,1361,1599,1895,2051,2643, Thermal fatigue 2241 2713 Thermal field calculation 913 Ti-15-3 379, 541, 785, 823, 1067, 1179, Thermal oxidation 2433, 3277 1227, 1331, 1607 Thermal properties measurements 411 TiAl based alloys 683, 1067, 2123, 2293, Thermal shock tests 2455 2301, 2317, 2339, 2361, 2417, 2627, Thermal spraying 589 2899, 3067, 3411 Thermal stability 1499, 1607, 1623, 2809 TiAl casting 2233 Thermo-cycling treatment 707 TiAl-Cr alloys 2325 LXXXII Subject Index

TiAl-(Cr, Si) alloys 2285 Ti-6Al-4V TiAl engine valves 3011 - A380 application 2667 TiAl-Fe alloys 2309 - α case 2051 TiAl ingot production 2123 - Aero-engine material 2845 TiAl heat treatments 2123 - Armor plate 173, 3125 TiAl intermetallic compound 2201, 2209, - Aircraft applications 2659, 2697 2309 - Billets 305, 313, 321 TiAl-(Mo, Cr, Si) alloys 2249 - Biomedical application 3213, 3237, TiAl-(Mo, Cu, Si) alloys 2331 3245, 3323, 3331, 3339, 3361 TiAl-(Mo, Si) alloys 2293 - Cast slabs 181 -TiAl(Nb, Cr, B) alloys 2257, 2277 - Casting 431, 439, 447, 455, 2635, 2681 TiAl phase diagrams 2123 - Compressor disk 2853 TiAl powder processing 2123 - Connecting rod 3051, 3059 TiAl sheet joints 2277 - Corrosion behavior 3205 TiAl/steel joining 2265, 2271 - Deformation behavior 1453, 1469, 1477

Ti2AlNb based alloys 2137, 2145, 2153, - Diffusion bonding 675 2161, 2185 - EDM 2883

Ti2AlNb based matrix composites 2471, - Engine valves 3075 2479, 2601 - Extrusions 329

Ti2AlNb phase 2177 - Fatigue 1753, 1759, 1767, 1775, 1783, Ti3Al phase 2177 1791, 1799, 1807, 2697 Ti-Ag alloys 3229 - Fatigue crack propagation 1941, 1957, Ti-Al alloys 1017, 1075, 1377, 2011 1979, 2837 Ti-Al-Cr-Y-N coatings 2441 - Fine grained sheets 569, 577 Ti-Al-Fe-Mo alloys 3083 - FOD 2761 Ti-Al-V alloys 533, 1389 - Forging 2793 Ti-1.5Al 3019 - Forming 597 Ti-2Al-2.5Zr 1731, 1815, 2041 - Fretting fatigue 1675, 1707, 2769 Ti-3Al-5Mo-5V-4Cr-2Zr 1575 - HDH process 1715 Ti-3Al-2.5V 2033, 2719 - High temperature deformation 371, 379, Ti-4.5Al-5Mo-1.5Cr 643 1461 Ti-4.5Al-2.3V 2041 - Laser fabricated 525, 541, 549 Ti-5Al-2.5Fe 495 - Machining 815, 839, 847 Ti-5Al-1Sn-lZr-1V-0.8Mo 651, 2083 - Melting 189, 197 Ti-5Al-2.5Sn ELI 1745, 3149 - Modelling of properties 1413 Ti-5Al-4V-(Mo, Fe, Si) 3027 - Phase transformation 1251 Ti-5.5Al-1Fe 1251 - Physical properties 411 Ti-6Al-4Fe-(0.1-1.0)Si 1123 - P/M 495 Ti-6Al-2Mo-2Cr 1505 - Plate 181 Ti-6Al-2Nb-lMo-1Ta 1421 - Porous material 3157 Ti-6Al-7Nb 1017, 3237, 3253, 3377 - Recrystallization 1211 Ti-6Al-4.8Sn-2Zr-1Mo-0.4Si-lNd 1115, - Sheet 2719 1925 Subject Index LXXXIII

Ti-6Al-4V (cont) Ti-46.5Al-5Nb (at%) 2241 - Sheet forming 569, 589, 619 Ti-47Al-0.3Ce (at%) 2355 - Solidification 157 Ti-47Al-0.3Y (at%) 2355 - SPF 597 Ti-48Al-1Cr (at%) 2449 - SPF/DB 2673 Ti-48Al-2Cr-2Nb (at%) 1377, 2217, 2225, - Spheroidization 1243 2347, 2369, 2441 - Steam turbine blades 2991 Ti-48Al-2Cr-2Nb-lB (at%) 2433 - Surface treatment 883, 905, 921, 929, Ti-48Al-4Cr (at%) 2449 935, 941, 949, 971, 979, 993, 1001, TiB 2547 1017, 1031, 1039, 1045, 1053, 1059, TiB additions 1235 1369, 2801 TiB particles 2555, 2601 - Tensile properties at 20K 3197 TiB whiskers 2495 - Texture 1211, 1275, 1283, 1299, 1307, TiB2 2517 1377 Ti-B19 1195, 1575 - Thermo-mechanical treatment 1259, Ti-B20 1591 1267 Ti borides 399, 971 - Transformation kinetics 1131 Ti butts 777 - VAR 165 TiC formation 2511 - Wear 1667, 1691, 3245 TiC particles 2517, 2539, 2563, 2609 - Welding 721, 729, 785, 799, 2651 Ti carbides 971 Ti-

6Al-4V/IMI 550 diffusion bonding 675 TiCl4 production 129,141

Ti-6Al-4V/TiB 2547 TiCl4 technologies 129 Ti-6Al-4V ELI 699, 1485, 3197, 3353 Ti cladding 745, 753 Ti- 6Al-4V matrix composites 2463, 2495, Ti-Cr-Cu alloys 3261

2539, 2547, 2609 Ti-2.5Cu 1017 Ti-6Al-4V VLI 2083 Ti-Fe alloys matrix composites 2555 Ti-6Al-4V-1Ru 2951 Ti-Fe-B 2555 Ti-24Al-17Nb-0.5Mo (at%) 2169 Ti-1 Fe-O-N 737 Ti-44Al-8Nb-1B (at%) 411 Ti-(1.5-2.2)Fe-O-N 1107 Ti-45Al-2Nb-2Mn (at%) 2409 Ti-4.3Fe-7.1Cr-(0-3)Al 1583 Ti-45Al-(5-10)Nb (at%) 2393, 2899 Ti-8Fe-8Ta 3173 Ti-45Al-8Nb (at%) 2441 Ti-8Fe-8Ta-4Zr 3173 Ti-46Al-4 (Cr, Nb, B) (at%) 2277 Ti hydride powder 511 Ti-46Al-1.5 (Mo, Cr) -0.2Si (at%) 2249 TIG welding 659, 721, 729, 737 Ti-46Al-4Nb-4Hf-0.1Si-1B (at%) 2369 Ti matrix composites 2463, 2503, 2511 Ti-46Al-8Nb (at%) 2369 Ti 8LC 3083 Ti-46Al-8Nb-1B (at%) 2369 Ti 12LC 365, 3083 Ti-46Al-9Nb (at%) 2385, 2401 Ti-Mo alloys 533, 957, 1511 Ti-46.5Al-4 (Cr, Nb, Ta, B) alloys (at%) Ti-Mo-Fe-Ta alloys 3165 2377 Ti-(8-11)Mo-4Nb-2V-3Al 1535, 1543 Ti-46.5Al-4 (Nb, Mn, Cr, Si, B) alloys TiN phase 2115 (at%) 2385, 2425 Ti-Nb alloys 2075, 3315 LXXXIV Subject Index

Ti-Nb-Al alloys 1139, 3385 Tweed structure 1179, 1567 Ti-23Nb-0.7Ta-2Zr-1.20 (at%) 1527 Twinning 1429, 1493, 1511, 1527, 1691, Ti-29Nb-13Ta-4.6Zr 3181, 3189, 3245, 1815, 2019, 2145, 2301, 2377 3269 Ti-35Nb-7Zr-5Ta 1651 U Ti-40Nb 2075 Ultra-fine grain size 1437, 1445 Ti-45Nb 2075 Ultra-high strength 1519, 1527 TiNi based alloys 393, 463, 861, 1903, Ultrasonic inspection 2635 3221 Ultrasonic noise 297 Ti nitride 891, 929, 971, 2115 Upset pressure 793

TiO2 245, 253, 261, 277 Upset time 793 TiO2 coatings 3277, 3345 Upsetting 379, 549 TiO2 ores 129 Ti powder 261, 487 V Ti-Si alloys 2059 Vacuum distillation 141 Ti-Si intermetallics 2193 Vacuum induction melting 2217, 2225, Ti silicides 2059 2347 Ti-Sn alloys 2115 Vacuum skull melting 2285 Ti-Ta alloys 3315 Valence charge density 2177 Ti-V alloys 533 Valence number 1519 Ti-1.6V 2019 Vanadium concentration 847 Ti-20V-4Al-1Sn 3141 VAR 149, 157, 165, 205, 2209, 2285, 2737 Ti-23Zr-10Nb 2075 VAR operating parameters 157 Ti-23Zr-18Nb-3V-1Al 1551 Variable amplitude loading 1979 Tool deformation 785 Vibration behavior 2975 Tool fracture 785 Vibrostrengthening 1053 Tool life 785, 815 Videometry 411 Tool wear 785, 831, 2817 Viscoplasticity formulation 2301 Topography 1941 Void formation 1485 Torsion test 1243 VT 3-1 875 Torsional plastometer 371 VT 6 707, 2777, 2991 TP-650 matrix composites 2517 VT 8 875 Transformation kinetics 1091, 1099, 1171 VT 8M 2777 Transportation 2999 VT 9 707, 875, 2777 Tri-modal microstructure 1623 VT 16 385, 1307 Tribo-layer 1691 VT 18 875 Tribological properties 987, 1699 VT 20 707, 875 Truck beam 2643 VT 22 707, 1227, 1307, 2643, 2713 TTT diagram 1099, 1131, 1397 VT 23 707, 831, 875 Turbocharger 69, 3067, 3411 VT 32 707 Turning 815, 2883 Subject Index LXXXV

W Welding wire 761

W-modified Ti2AlNb 2161 Welding zone 715, 793, 2265, 2753 Water vapor effect 1949, 1995 Wire feedability 761 Wear 1667, 1683, 1691, 1699, 1707, 2433 Wiredrawing 357

Wear mechanism 1699 WO3 coating 3361 Wear of cutting tools 2293 Work hardening 823, 1017 Wear resistance 557, 899, 905, 929, 935, Workability 3089 993, 1001, 1009, 1031, 2555, 3245 Wrought plates 2285 Weight loss 993 Wrought processing 1, 285 Weight reduction 1839 Weld bead 761 X Weld repair 431 X-ray diffraction 1045, 1107, 1115, 1131, Weld seams 2753 1155,1163,1275,1715,2051,2115, Weldability 737, 2967, 3097, 3141 2193, 2331, 2745, 2801 Welded joints 667, 699, 707, 737, 2265, X-ray photoelectron analysis (XPS) 3285 2627, 2959 Welding 27, 49, 69, 557, 659, 699, 707, Y

715, 721, 729, 737, 745, 753, 761, 785, Y203 additions 1235 793, 799, 807, 2265, 2271, 2745, 2753, 2867, 2875, 2923, 2943, 2975 Z Welding parameters 721 Zener-Hollomon parameter 1219 Welding speed 2651