Mechanical Properties of Titanium Foams Having Disordered and Ordered Cell Structures 不規則及び規則セル構造を有するポーラスチタンの機械 的特性 Yue xue-zheng Department of Aerospace Engineering Graduate School of System Design Tokyo Metropolitan University January 2018 1 Mechanical Properties of Titanium Foams Having Disordered and Ordered Cell Structures 不規則及び規則セル構造を有するポーラスチタンの機械的特性 by Yue xuezheng Student ID 15991504 Submitted to the Department of Aerospace Engineering, Graduate School of System Design, in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Aerospace Engineering at TOKYO METROPOLITAN UNIVERSITY December 2017 Certified by advisor Professor Koichi Kitazono Department of Aerospace Engineering Graduate School of System Design Tokyo Metropolitan University 2 Contents Chapter 1: Introduction ...................................................................................... 10 1.1 Metal foam ...................................................................................... 10 1.2 Application of metal foam .................................................................. 12 1.2.1 Automobile industry .................................................................... 12 1.2.2 High-speed trains ........................................................................ 12 1.2.3 Chemical industry ....................................................................... 13 1.2.4 Aerospace industry ...................................................................... 13 1.2.5 Biological implant materials ........................................................ 14 1.3 Different material metal foam ............................................................... 16 1.3.1 Gold material ............................................................................. 16 1.3.2 Magnesium material .................................................................... 17 1.3.3 Copper material .......................................................................... 17 1.3.4 Aluminum material ..................................................................... 18 1.3.5 Stainless steel material ................................................................ 20 1.3.6 Titanium material ........................................................................ 21 1.4 Manufacture method .......................................................................... 26 1.4.1 Melt foaming method ................................................................. 26 1.4.2 Casting method. .......................................................................... 27 1.4.3 Powder metallurgy. .................................................................... 28 1.4.4 Chemical or physical deposition of metal or plastic foams. ............. 30 1.4.5 3D Printing or additive manufacturing. ......................................... 30 1.5 Compare with traditional techniques and additive manufacturing. ........... 36 1.5.1 The Traditional melt foaming technology ...................................... 39 3 1.5.2 The Traditional vacuum flow casting ............................................ 42 1.5.3 The Traditional powder metallurgy ............................................... 43 1.5.4 Additive manufacturing ............................................................... 43 1.5.5 AM technology mainly has the following salient features: ............... 45 1.5.6 Disadvantages of AM technology ................................................. 46 1.6 Theory .............................................................................................. 47 1.6.1 Porosity, pore size and pore distribution. ....................................... 47 1.6.2 Energy absorption ....................................................................... 49 1.7 Summary ........................................................................................... 50 1.7.1 Scope of the thesis ...................................................................... 50 1.7.2 Outline of thesis ......................................................................... 51 References ................................................................................................ 54 Chapter 2: Strain rate sensitivity of open-cell titanium foam at elevated temperature 63 2.1 Introduction ....................................................................................... 63 2.2 Experimental procedure....................................................................... 64 2.3 Results .............................................................................................. 67 2.4 Discussion ......................................................................................... 71 2.5 Conclusions ....................................................................................... 76 References ................................................................................................ 77 Chapter 3: Compressive behavior of open-cell titanium foams with different unit cell geometries.......................................................................................................... 80 3.1 Introduction ....................................................................................... 80 3.2 Experimental procedure....................................................................... 81 3.3 Results .............................................................................................. 87 4 3.3.1 Effect of porosity ........................................................................ 87 3.3.2 Effect of shape of unit cell ........................................................... 89 3.3.3 Effect of compression direction .................................................... 89 3.3.4 Macroscopic shear bands ............................................................. 90 3.4 Discussion ......................................................................................... 91 3.5 Conclusions ....................................................................................... 98 References ................................................................................................ 99 Chapter 4: Effect of heat treatment on mechanical properties of porous Ti-6Al-4V alloy manufactured by 3D selective laser melting ................................................. 101 4.1 Introduction ..................................................................................... 101 4.2 Materials and Methods ..................................................................... 103 4.3 Results ............................................................................................ 106 4.3.1 Macrostructure and Microstructure for specimen .......................... 106 4.3.2 Vickers hardness ........................................................................ 111 4.3.3 Compressive characterization ..................................................... 112 4.3.4 Energy absorption ..................................................................... 114 4.4 Discussion ....................................................................................... 116 4.4.1 Microstructure and fracture surface ............................................. 116 4.4.2 Compressive characteristics ....................................................... 117 4.4.3 Energy absorption characteristics ...................................... 117 4.5 Conclusion ...................................................................................... 119 References .............................................................................................. 120 Chapter 5: Conclusions and future works ........................................................... 122 5.1 Conclusions ..................................................................................... 122 5 5.1.1 Strain rate sensitivity of open-cell titanium foam at elevated temperature ........................................................................................ 122 5.1.2 Compressive behavior of open-cell titanium foams with different unit cell geometries ................................................................................... 122 5.2 Suggestions for future work ................................................................. 125 5.2.1 Finite element analysis dynamic properties of open cell titanium foam by additive manufacturing ................................................................... 125 5.2.2 Effect of voronoi cell structures on mechanical properties of titanium foams ................................................................................................ 126 Appendix ................................................................................................ 127 Appendix A. Publications .................................................................. 127 Appendix B. Conferences and Presentations ........................................ 128 6 Titanium and titanium alloy are metal material with high tensile strength to density ratio, high corrosion resistance, fatigue resistance, high crack resistance and so on. Metal foams have many advance properties for example: low densities and novel physical, mechanical, thermal, electrical and acoustic properties. Manufacturing titanium foams traditional method and additive manufacturing method are reviewed. The powder sinter process generally consists powder blending, die compaction, and sintering. Compaction is generally performed at room temperature, and the elevated-temperature process of sintering is usually conducted at