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Dislocation Structures in Germanium Single Chrystals Deformed in a Dual Glide Orientation

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Dislocation Structures in Germanium Single Chrystals Deformed in a Dual Glide Orientation This dissertation has been 69-22,162 microfilmed exactly as received LAKE, Peter Babcock, 1942- DISLOCATION STRUCTURES IN GERMANIUM SINGLE CRYSTALS DEFORMED IN A DUAL GLIDE ORIENTATION. The Ohio State University, Ph.D., 1969 Engineering, metallurgy University Microfilms, Inc., Ann Arbor, Michigan DISLOCATION STRUCTURES IN GERMANIUM SINGLE CRYSTALS DEFORMED IN A DUAL GLIDE ORIENTATION DISSERTATION Presented in Partial Fulfillment of the Requirements for the Degree Doctor of Philosophy in the Graduate School of The Ohio State University By Peter Babcock Lake, B.S. * * * * « The Ohio State University 1969 Approved by , / /' < <•■'( A Adviser Department of .Metallurgical Engineering Dedicated to my wife Melinda ii ACKNOWLEDGMENTS I would like to acknowledge the assistance and advice of my adviser. Professor John Hirth. Among the others who helped me greatly with this work, I would like to especially thank Professor Glyn Meyrick, and Mssrs. Ross Justus and Henry Pagean. iii VITA June 15. 1942 Born - Bethlehem, Pennsylvania 1964 . „ . , B.S», The Pennsylvania State University 1964 1969 . National Science Foundation Trainee, Department of Metallurgical Engineering, The Ohio State University iv CONTENTS Page ACKNOWLEDGMENTS ......... ................................ ill VITA ........................................................ Iv LIST OP PLATES .............................................. vil LIST OP FIGURES ............................................ *iv LIST OP TABLES .............................................. xix Chapter I. INTRODUCTION .................................... 1 A. Material Selection B. Dislocations in the Diamond Cubic Structure C. Previous Investigations of the Deformation Behavior and Dislocation Structure of Germanium D. Low Angle Grain Boundaries E. Studies of Equilibrium Node Angles In Iron P. Low Angle Boundaries in Face-Centered Cubic Crystals G. Conclusions Drawn from the Introductory Chapter II. EXPERIMENTAL PROCEDURES AND TECHNIQUES .... 66 A. Introduction B. Technique Used for Producing Twist Networks C. Specimen Preparation and Deformation D. Equations for Calculating True Glide Stress and Strain III. RESULTS— DEFORMATION CURVES AND SLIP TRACE ANALYSIS .......................................... 100 A. Stress-Strain Curves B, Observations of Slip Plane Rotation and Crystal Surfaces v CON'j'Er: j S ( Could , } Chaptc r Rage iv . d is c u s s r o:: os Mucsoscoiir c C:i/ . -r.C'i■ jri ■■ j cs oi-’ r.iv/ii:■. : defoim atio':..........................................................13^ A . 1 ma I T’> I i V' V c j u - R in;-1f- R 1 -t P v. PhOCEueoSs and techie !dues for electron microscopy .................. 159 A. Tn 5 Jin :: nr J’.. Opera tin'; To ehni quc s Vi. kesudvs—electron MrcRosco:-'Y ....................................................175 _ j> A. Cry stall a Strained at 5 x 10 ‘/sec and 5 x 10 “ 3 /s e c B. Dislocation Configurations in Annealed Cry stain VI I. DIB CUBS! C D ! ..............................................................................................2hlj A. The Bnorrp,' of Straight Dis!ocatlons B. Application of an Analytical Method to Obtain Values of K/t(0°) and K^(60°) C. Method Used to Obtain a Working Equation for the Variation of K^C/3) i:.tth/3 D. Derivation of the Expected Node1 Angies E. The Dislocation Structure in Ar,-defamed Crystals F. Dislocation Structui^es in Annealed Crystalo v i i i . con chu s i o n s .............................................................................................................3^6 ATT EN D U E S A........................................................................................................................................3^9 B ......................... 39? C................................................................................................................................ 399 D ......................... 362 E........................................................................................................................................365 REFERENCES...... 372 vi PLATES Plate Page 1. Kink Bands in Single S l i p ...................... 30 2. Dislocations on the (111) Twist Plane ....... 34 3. Dissociated Nodes in Silicon ..................... 35 Undissociated Nodes in Germanium ......... 35 5. Dislocation Networks in I r o n .................. 53 6. Macroscopic Shapes of Specimens C-55, C-53, C-51 and C - 5 0 ....................................121 7. Slip Traces on (Oil) Pace— Set I .................... 124 8. Slip Traces on (Oil) Face— Set I I .................... 125 9. Slip Traces on (8ll) F a c e ............................. 128 10. Surface Undulations on (8ll) F a c e ................... 129 11. High Magnification Interference Contours .... 130 12. Specimen C-42, (Oil) F a c e ..............................131 13. Specimen C-33, (Oil) F a c e ..............................131 14. Specimen C-39, (Oil) F a c e ..............................133 15. Specimen C-37, (Oil) F a c e ..............................133 16. KIkuchi and Diffraction Patterns for Germanium . 170 17. Specimen C-26, Strained 4.3? l8l 18. Specimen C-26, Strained 4 . 3 ? ...................... 181 19. Specimen C-26, Strained 4 . 3 ? ................. 181 20. Specimen C-29, Strained 6.2? 182 21. Specimen C-29, Strained 6.2? 182 vii PLATES (Contd.) Plate Page 22. Specimen C-29, Strained 6 , 2 ? ..................... 182 23. Specimen C-29, Strained 6,2? 183 24. Specimen C-55, Strained 12 . 6 ? ........................ 18*4 25. Specimen C-55, Strained 12 . 6 ? ........................ 184 26. Specimen C-55, Strained 12.6? ........................ 18*4 27. Specimen C-55, Strained 12.6? ..................... 185 28. Specimen C-55, Strained 12 . 6 ? ........................ 186 29. Specimen C-55, Strained 12.6? ..................... 186 30. SpecimenC-55, Strained 12.6? ..................... 186 31. Specimen C-42, Strained 4.2? 187 32. Specimen C-42, Strained 4.2? ..... 187 33. Specimen C-42, Strained 4 . 2 ? ........................187 34. Specimen C-42, Strained 4.2? 188 35. Specimen C-42, Strained 4.2? 188 36. Specimen C-42, Strained 4.2? 188 37* Specimen C-36, Strained 8.6? 189 38. Specimen C-36, Strained 8.6? 189 39. Specimen C-36, Strained 8.6? 189 40. Specimen C-38, Strained 16.0? ..... ......... 190 41. Specimen C-38, Strained 16.0? ................ 190 42. Specimen C-38, Strained 16.0? ..................... 190 43. Specimen C-38, Strained 16.0? ..................... 190 viii PLATES (Contd.) Plate Page 44. Specimen C-40, Strained 16. 0% . 191 45. Specimen C-40, Strained 16.0% , . 191 46. Specimen C-40, Strained 16. 0% . 191 47. Specimen 0-40, Strained 16. 0% 191 48. Specimen C-37, Strained 25. 4% . 192 49. Specimen C-37, Strained 25. 4$ . 192 50. Specimen C-37, Strained 25.4$ . 192 51. Specimen C-26, Annealed at 850°C for 36 Hours . 203 52. Specimen C-26, Annealed at 850°C for 36 Hours . 203 53. Specimen C-26, Annealed at 850°C for 36 Hours . 203 54. Specimen C-26, Annealed at 850°C for 36 Hours . 204 55. Specimen C-26, Annealed at 850°C for 36 Hours . 204 56. Specimen C-26, Annealed at 850°C for 36 Hours . 204 57. Specimen C-55, Annealed at 750°C for 24 Hours . , 205 58. Specimen C-55, Annealed at 750°C for 24 Hours . 205 59. Specimen C-55, Annealed at 750°C for 24 Hours . 205 60. Specimen C-55, Annealed at 750°C for 24 Hours . 205 61. Specimen C-55, Annealed at 850°C for 24 Hours . 206 62. Specimen C-55, Annealed at 850°C for 24 Hours . 206 63. Specimen C-55, Annealed at 850°C for 24 Hours . , 206 64. Specimen C-55, Annealed at 850°C for 24 Hours . 207 65. Specimen C-25, Annealed at 850°C for 36 Hours . 208 lx PLATES (Contd.) Plate Page o 00 o o 66. Specimen C-25, Annealed at U1 for 36 Hours * ft 209 67. Specimen C-25, Annealed at 850°C for 36 Hours • ft 210 68. Specimen C-25, Annealed at 850°C for 36 Hours • ft 210 69. Specimen C-25, Annealed at 850°C for 36 Hours • ft 210 70. Specimen 0-27, Annealed at 850°C for 36 Hours ft 211 71. Specimen C-27, Annealed at 850°C for 36 Hours • ft 211 72. Specimen C-27, Annealed at 850°C for 36 Hours • ft 211 73. Specimen C-27, Annealed at 850°C for 36 Hours ft ft 211 74. Specimen C-27, Annealed at 850°C for 36 Hours • ft 212 75. Specimen C-27, Annealed at 850°C for 36 Hours • ft 212 76. Specimen C-27, Annealed at 850°C for 36 Hours • ft 212 77. Specimen C-27, Annealed at 850°C for 36 Hours • ft 212 00 t- . Specimen C-27, Annealed at 850°C for 36 Hours * ft 213 79. Specimen C-27, Annealed at 850°C for 36 Hours * ft 214 80. Specimen C-27, Annealed at 850°C for 36 Hours -• ft 214 81. Specimen C-42, Annealed at 700°C for 24 Hours ft ft 230 GO fu * Specimen C-42, Annealed at 700°C for 24 Hours • ft 2 30 83. Specimen C-36, Annealed at 700°C for 24 Hours • ft 2 31 84. Specimen C-36, Annealed at 700°C for 24 Hours •• 231 00 in * Specimen C-38, Annealed at 700°C for 6 Hours ft ft 232 86. Specimen C-38, Annealed at 700°C for 6 Hours * ft 232 87. Specimen C-38, Annealed at 700 °c for 6 Hours • ft 232 88. Specimen C-38, Annealed at 700 °c for 24 Hours • ft 233 x PLATES (Contd.) Plate Page 89. Specimen C-38 Annealed at 700°C for 24 Hours • . 233 90. Specimen C-38 Annealed at 700°C for 24 Hours *• 233 91. Specimen C-38 Annealed at 700°C for 24 Hours •• 234 92. Specimen C-38 Annealed at 700° C for 24 Hours *• 234 93. Specimen C-38 Annealed at 700° C for 24 Hours • • 234 94. Specimen C-40 Annealed at 700°C for 24 Hours • 235 95. Specimen C-40 Annealed at 700°C for 24 Hours *• 235 96. Specimen C-43 Annealed at 700°C for 24 Hours ** 236 97. Specimen C-43 Annealed at 700°C for 24 Hours • 2 36 98. Specimen C-43 Annealed at 700 °c for 24 Hours *• 236 99. Specimen C-37 Annealed at 700°C for 24 Hours ♦ * 237 100. Specimen C-37 Annealed at 700°C for 24 Hours •• 2 37 101. Specimen C-37 Annealed at 700 °c for 24 Hours * ♦ 237 102.
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  • Role of Interfaces in Deformation and Fracture of Ordered Intermetallics
    “Thesubmmed manuscript has been authored by a mtactw of the U.S. Government under contract No. DE-ACOS- 96OR22464. Accordingly. the US. Government retains a nonBxcIusNe, myaWfree tlcense to publish or reproduce the published form of this cmtnbulon. or allow others lo do so. for U.S. Government purposes.“ cd rev 1/9/97 Draft.2--Ecoie “Dislocations 96” Interfaces and Plasticity (to be submitted) Role of Interfaces in Deformation and Fracture of Ordered Intermetallics M. H, Yo0 and C. L. Fu Metals and Ceramics Division, Oak Ridge National Luboratory, Oak Ridge, TN 37831 -6115, USA Abstract : While sub- and grain-boundaries are the primary dislocation sources in L12 alloys, yield and flow stresses are strongly influenced by the multiplication and exhaustion of mobile dislocations from the secondary sources. The concept of enhanced microplasticity at grain boundaries due to chemical disordering is well supported by theoretical modeling, but no conclusive direct evidence exist for Ni3AI bicrystals. The strong plastic anisotropy reported in TiAl PST crystals is attributed in part to the localized slip along lamellar interfaces, thus lowering the yield stress for soft orientations. Calculations of work of adhesion suggest that, intrinsically, interfacial cracking is more likely to initiate on yly-type interfaces than on the &/y boundary. I, Introduction As compared to fcc metals and alloys, ordered intermetallic compounds of the L12 structure are generally known to possess high strength at elevated temperatures due to the relatively low atomic Wsivity and dislocation mobility. The anomalous (positive) temperature dependence of yield stress observed in certain ordered intermetallics of relatively high ordering energy, e.g., Ni3Al [1,2],has been the subject of active research in recent years [3-71.
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