本研究使用單軸壓縮對AZ31B 鎂合金熱軋延材進行ND 方向及RD 方向試驗，分別在不同溫度、應變速率與變形量觀察材料內部的變形行為。
在變形溫度 200oC 以下，沿板材ND 進行壓縮試驗，結果顯示材料會生成板狀變形集中帶。起初變形帶的方位是平行板材TD 方向與壓延面交約25o，隨後材料沿變形帶處破裂。板狀變形帶的組織因變形條件不同而有不同的組織，分別是含變形雙晶、雙晶誘導動態再結晶與動態再結晶的變形組織。另外，AZ31B 鎂合金晶界動態再結晶的成核機制為晶界凸出，隨後於原始晶界位置形成低角度邊界，隨著變形量增加，低角度邊界轉變成高角度晶界並形成動態再結晶晶粒。當壓縮溫度提升至300 oC 時，變形相當的均勻無變形集中帶形成。在RD 壓縮與變形溫度為200 oC，應變速率為10-3 s-1，在變形過程中材料內部隨應變量的增加依序產生均勻的拉伸雙晶、動態再結晶與對稱且細小的變形帶，因此材料的變形比ND 壓縮來的均勻。本研究結果顯示當晶體的C軸與材料的壓縮軸垂直時能避免AZ31 鎂合金軋延板材的應變集中現象，使材料較能均勻變形。

none

總目錄 I
表目錄 IV
圖目錄 V
第一章 前言 1
第二章 文獻回顧 2
2-1 鎂合金的變形 2
2-1-1 室溫變形 2
2-1-1-1 差排滑移 2
2-1-1-2 變形雙晶 3
拉伸雙晶(tension twin) 3
壓縮雙晶(compression twin) 4
二次雙晶(double twin) 4
2-1-2 鎂合金的高溫變形行為 6
2-1-2-1 動態再結晶行為 7
2-1-2-2 變形雙晶誘導動態再結晶現象 10
變形雙晶與晶界交會處 11
拉伸雙晶晶界處 11
拉伸雙晶內 12
二次雙晶晶界處 12
2-1-2-3 晶界滑移 (grain boundary sliding) 12
2-2 織構(texture)與相關變形行為 14
2-3 鎂合金的變形集中現象 16
2-3-1 常溫變形集中現象 17
2-3-2 高溫變形集中現象 18
第三章 實驗方法 22
3-1 實驗材料 22
3-2 壓縮試驗 22
3-3 光學顯微鏡與掃瞄式電子顯微鏡的試片製備 23
3-4 晶粒尺寸的量測與晶界凸出尺寸的量測： 23
3-5 EBSD 的試片製備及量測 24
3-6 穿透式電子顯微鏡的試片製備 25
3-7 變形集中角度的量測 25
第四章 實驗結果 26
4-1 ND 壓縮試驗結果 26
4-1-1 室溫與100 oC 的變形組織 26
4-1-2 變形溫度為200 oC，應變速率為10-1 s-1 的變形組織 27
4-1-3 變形溫度為200 oC，應變速率為10-3 s-1 的變形組織 29
4-1-4 變形溫度為300 oC，應變速率為10-3 s-1 的變形組織 33
4-2 RD 壓縮變形 33
4-2-1 室溫變形組織 33
4-2-2 200 oC，應變速率為10-3 s-1 的變形組織 34
第五章 討論 37
5-1 動態再結晶的成核機制 37
5-2 ND 壓縮變形集中帶 39
5-2-1 板材退火織構 39
5-2-2 雙晶變形帶(常溫與100 oC 的變形帶) 40
5-2-3 變形雙晶誘導動態再結晶變形集中帶的演化過程(200
oC ，應變速率為10-1 s-1 所形成的變形帶) 42
5-2-4 動態再結晶的變形集中帶演化過程(200 oC與應變速率為10-3 s-1 所形成的變形帶) 43
5-3 RD 壓縮變形 45
5-3-1 室溫變形 45
5-3-2 200 oC 變形 46
5-4 壓縮方向對變形不均勻性的影響 48
5-4-1 在200 oC，變形雙晶對動態再結晶的影響 48
5-4-2 變形帶的方位 50
5-4-3 在200 oC，變形集中與均勻變形的差異 51
5-5 變形組織與應變曲線之關係 51
第六章 結論 53
參考文獻 55

參考文獻
1. William, D.C., J., Materials Science and Engineering: An Introduction. 2007. John Wiley and Son.:p.185
2. Wonsiewicz, B.C. and Backofen, W.A., Plasticity of magnesium crystals. Transactions of AIME, 1967. 239: p. 1422.
3. Kelley, E.W. and Hosford, J.W.F., Plane-strain compression of magnesium and magnesium alloy crystal. Transactions of AIME, 1968. 242: p. 5.
4. Hauser, F.E., Starr, C.D., Tietz, L. and Dorn, J.E., Deformation mechanisms in polycrystalline aggregate of magnesium. Transactions of Metals, 1955. 47: p. 102.
5. Hauser, F.E., Landon, P.R., and Dorn, J.E., Deformation and fracture mechanisms of polycrystalline magnesium at low temperature. Transactions of Metals 1956. 48: p. 986.
6. Yoshinaga, H. and Horiuchi, R., On the non-basal slip in magnesium crystals. Transactions of the Japan Institute of Metals, 1963. 5: p. 14.
7. Roberts, C.S., Magnesium and Its alloys. 1960. John Wiley and Son.:p.88
8. Reed-Hill, R.E. and Robertson, W.D., Deformation of magnesium single crystals by non-basal slip. Journal of Metals, 1957. 5: p. 496.
9. Burke, E.C. and Hibbard, W.R.J., Plastic deformation of magnesium silngle crystals. Transactions of AIME, 1952. 194: p. 295.
10. Obara, T., Yoshinga, H. and Morozumi, S., [112 ‾2 ‾ ](112 ‾3) Slip system in magnesium. Acta Metallurgica, 1973. 21: p. 845.
11. Reed-Hill, R.E. and Robertson, W.D., Pyramidal slip in magnesium. Transactions of AIME, 1958. 212: p. 256.
12. Reed-Hill, R.E. and Robertson, W.D., The crystallographic characteristics of fracture in magnesium single crystals. Acta Metallurgica, 1957. 5: p. 728.
13. Hartt, W.H. and Reed-Hill, R.E., The irrational of second-order {101 ‾1}-{101 ‾2} twins in magnesium. Transactions of AIME, 1967. 239: p. 1511.
14. Hartt, W.H. and Reed-Hill, R.E., Internal deformation and fracture of second-order{101 ‾1}-{101 ‾2} twins in magnesium. Transactions of AIME, 1968. 242: p. 1127.
15. Yoshinaga, H. and Obara, T. and Morozumi, S., Twinning deformation in magnesium compressed along the c-axis. Materials Science and Engineering, 1973. 12: p. 255.
16. Yoshinaga, H. and Horiuchi, R., Deformation mechanisms in magnesium single crystals compressed in the direction parallel to the hexagonal axis. Transactions of the Japan Institute of Metals, 1963. 4: p. 1.
17. Reed-Hill, R.E., A study of the {101 ‾1} and {101 ‾3} twinning mode in magnesium. Transactions of AIME, 1960. 218: p. 554.
18. Koike, J., Enhanced deformation mechanisms by anisotropic plasticity in polycrystalline Mg alloys at room temperature. Metallurgical and Materials Transactions, 2005. 36A: p. 1689.
19. Barnett, M.R., Twinning and the ductility of magnesium alloys Part I: "Tension" twins. Materials Science and Engineering A, 2007. 464: p. 1.
20. Barnett, M.R., Twinning and the ductility of magnesium alloys Part II. "Contraction" twins. Materials Science and Engineering A, 2007. 464: p. 8.
21. Barnett, M.R., Keshavarz, Z. and Nave, M.D., Microstructural features of rolled Mg-3Al-1Zn. Metallurgical and Materials Transactions A, 2005. 36: p. 1697.
22. Nave, M.D. and Barnett, M.R., Microstructures and textures of pure magnesium deformed in plane-strain compression. Scripta Materialia, 2004. 51: p. 881.
23. Barnett, M.R., Nave, M.D. and Bettles, C.J., Deformation microstructures and textures of some cold rolled Mg alloys. Materials Science and Engineering A, 2004. 386: p. 205.
24. Cizek, P. and Barnett, M.R., Characteristics of the contraction twins formed close to the fracture surface in Mg-3Al-1Zn alloy deformed in tension. Scripta Materialia, 2008. 59: p. 959.
25. Reed-Hill, R.E. and Abbaschian, R., Physical Metallurgy Principle. 3ed. 1994, PWS publishing company.:p. 555.
26. Meyers, M.A., Vohringer, O. and Lubarda, V.A., The onset of twinning in metals: a constitutive description. Acta Materialia, 2001. 49: p. 4025.
27. Ecob, N. and Ralph, B., The effect of grain-size on deformation twinning in a textured zinc alloy. Journal of Materials Science, 1983. 18: p. 2419.
28. Barnett, M.R., A rationale for the strong dependence of mechanical twinning on grain size. Scripta Materialia, 2008. 59: p. 696.
29. Barnett, M.R., Keshavarz, Z., Beer, A.G. and Atwell, D., Influence of grain size on the compressive deformation of wrought Mg-3Al-1Zn. Acta Materialia, 2004. 52: p. 5093.
30. Barnett, M.R., A Taylor model based description of the proof stress of magnesium AZ31 during hot working. Metallurgical and Materials Transactions A, 2003. 34: p. 1799.


31. Ion, S.E., Humphreys, F.J. and White, S.H., Dynamic recrystallization and the development of microstructure during the high-temperature deformation of magnesium. Acta Metallurgica, 1982. 30: p. 1909.
32. Kaibyshev, R.O. and Sitdikov, O.S., The relation of crystallographic slip and dynamic recrystallization to the local migraion of grain boundary: I. experimental results. The Physics of Metals and Metallography, 1994. 78: p. 420.
33. Mwembela, A., Konopleva, E.B. and McQueen, H.J., Microstructural development in Mg alloy AZ31 during hot working. Scripta Materialia, 1997. 37: p. 1789.
34. Galiyev, A., Kaibyshev, R.O. and Gottstein, G., Correlation of plastic deformation and dynamic recrystallization in magnesium alloy ZK60. Acta Materialia, 2001. 49: p. 1199.
35. Beer, A.G. and Barnett, M.R., Microstructural development during hot working of Mg-3Al-1Zn. Metallurgical and Materials Transactions A, 2007. 38: p. 1856.
36. del Valle, J.A. and Ruano, O.A., Influence of texture on dynamic recrystallization and deformation mechanisms in rolled or ECAPed AZ31 magnesium alloy. Materials Science and Engineering A, 2008. 487: p. 473.
37. Al-Samman, T. and Gottstein, G., Dynamic recrystallization during high temperature deformation of magnesium. Materials Science and Engineering A, 2008. 490: p. 411.



38. Drury, M.R., Humphreys, F.J. and White, S.H., Large strain deformation studies using polycrystalline magnesium as a rock analog dynamic recrystallization mechanisms at high-temperatures. Physics of the Earth and Planetary Interiors, 1985. 40: p. 208.
39. Humphreys, F.J. and Hatherly, M., Recrystallization and related annealing phenomena. 1996, Pergamon press.:p.363.
40. Ding, S.X., Chang, C.P. and Kao, P.W., Effects of processing parameters on the grain refinement of magnesium alloy by equal-channel angular extrusion. Metallurgical and Materials Transactions A, 2009. 40: p. 415.
41. Beck, P.A. and Perry, P.R., Strain induced grain boundary migration in high purity aluminum. Jounal of Applied Physics, 1950. 21: p. 150.
42. Bailey, J.E. and Hirsch, P.B., Recrystallization process in some polycrystalline metals. Proceedings of the Royal Society of London Series A, 1962. 267: p. 11.
43. Bailey, J.E., Electron microscope observations on the annealing processes occurring in cold-worked silver. Philosophical Magazine, 1960. 5: p. 833.
44. Luton, M.J. and Sellars, C.M., Dynamic recrystallization in nickel and nickel-iron alloys during high temperature deformation. Acta Metallurgica, 1969. 17: p. 1033.
45. Derby, B. and Ashby, M.F., On dynamic recrystallization. Scripta Metallurgica, 1987. 21: p. 879.
46. Roberts, W. and Ahlblom, B., Nucleation criterion for dynamic recrystallization during hot working. Acta Metallurgica, 1978. 26: p. 801.


47. Bellier, S.P. and Doherty, R.D., Structure of deformed aluminum and its recrystallization - investigations with transmission kossel diffraction. Acta Metallurgica, 1977. 25: p. 52.
48. Jones, A.R., Ralph, B. and Hansen, N., Subgrain coalescence and the nucleation of recrystallization at grain-boundaries in aluminum. Proceedings of the Royal Society of London Series A, 1979. 368: p. 345.
49. Hu, H., Direct observations on annealing of a Si-Fe crystal in electron microscope. Transactions of AIME, 1962. 224: p. 75.
50. Doherty, R.D. and Cahn, R.W., Nucleation of new grains in recrystallization of cold-worked metals. Journal of the Less-Common Metals, 1972. 28: p. 279.
51. Hurley, P.J. and Humphreys, F.J., Modelling the recrystallization of single-phase aluminium. Acta Materialia, 2003. 51: p. 3779.
52. Humphreys, F.J., A unified theory of recovery, recrystallization and grain growth, based on the stability and growth of cellular microstructures: The basic model. Acta Materialia, 1997. 45: p. 4231.
53. Frommert, M. and Gottstein, G., Mechanical behavior and microstructure evolution during steady-state dynamic recrystallization in the austenitic steel 800H. Materials Science and Engineering A, 2009. 506: p. 101.
54. Belyakov, A., Miura, H.and Sakai, T., Dynamic recrystallization under warm deformation of a 304 type austenitic stainless steel. Materials Science and Engineering, 1998. A 255: p. 139.
55. Ito, T., Taketani, T. and Nakayama, Y., Dynamic recrystallization by the bulging of grain-boundaries in polycrystalline dilute copper-alloys. Scripta Metallurgica, 1986. 20: p. 1329.

56. Miura, H. Sakai, T. Mongawa, R. and Gottstein, G., Nucleation of dynamic recrystallization at grain boundaries in copper bicrystals. Scripta Materialia, 2004. 51: p. 671.
57. Miura, H., Ozama, M., Mongawa, R. and Sakai, T., Strain-rate effect, on dynamic recrystallization at grain boundary in Cu alloy bicrystal. Scripta Materialia, 2003. 48: p. 1501.
58. Miura, H., Sakai, T., Hanaji, H. and Jonas, J.J., Preferential nucleation of dynamic recrystallization at triple junctions. Scripta Materialia, 2004. 50: p. 65.
59. Ponge, D. and Gottstein, G., Necklace formation during dynamic recrystallization: Mechanisms and impact on flow behavior. Acta Materialia, 1997. 46: p. 69.
60. Kaibyshev, R.O. and Sitdikov, O.S., On the role of twinning in dynamic receystallization. The Physics of Metals and Metallography, 2000. 89: p. 384.
61. Myshlyaev, M.M., McQueen, H.J., Mwembela and Kpnopleva, E., Twinning, dynamic recovery and recrystallization in hot worked Mg-Al-Zn alloy. Materials Science and Engineering A, 2002. 337: p. 121.
62. Lee, B.H., Bang, W. Ahn, S. and Lee, C.S., Effects of temperature and strain rate on the high-temperature workability of strip-cast Mg-3Al-1Zn alloy. Metallurgical and Materials Transactions, 2008. A39: p. 1426.
63. Yin, D.L., Zhang, K.F., Wang, G.F. and Han, W.R., Warm deformation behavior of hot-rolled AZ31 Mg alloy. Materials Science and Engineering, 2005 A. 392: p. 320.


64. Koike, J., Ohyama, R., Kobayashi, T. Suzuki, M. and Maruyama, K., Grain-boundary sliding in AZ31 magnesium alloys at room temperature to 523 K. Materials Transactions, 2003. 44: p. 445.
65. Tan, J.C. and Tan, M.J., Superplasticity in a rolled Mg-3A1-1Zn alloy by two-stage deformation method. Scripta Materialia, 2002. 47: p. 101.
66. Tan, J.C. and Tan, M.J., Superplasticity and grain boundary sliding characteristics in two stage deformation of Mg-3Al-lZn alloy sheet. Materials Science and Engineering A, 2003. 339: p. 81.
67. Wu, X. and Liu, Y., Superplasticity of coarse-grained magnesium alloy. Scripta Materialia, 2002. 46: p. 269.
68. Vespa, G., Mackenzie, L.W.F., Verma, R., Zarandi, F., Essadiqi, E. and Yue, S., The influence of the as-hot rolled microstructure on the elevated temperature mechanical properties of magnesium AZ31 sheet. Materials Science and Engineering A, 2008. 487: p. 243.
69. Del Valle, J.A., Perez-Prado,M.T. and Ruano, O.A., Deformation mechanisms responsible for the high ductility in a Mg AZ31 alloy analyzed by electron backscattered diffraction. Metallurgical and Materials Transactions A, 2005. 36: p. 1427.
70. Panicker, R., ChoKshi, A.H., Mishra, R.K., Verma, R and Krajewski, P.E., Microstructural evolution and grain boundary sliding in a superplastic magnesium AZ31 alloy. Acta Materialia, 2009. 57: p. 3683.
71. Bell, R.L., Graeme-Barber, C. and Langdon, T.G., Contribution of grain boundary sliding to overall strain of a polycrystal. Transactions of AIME, 1967. 239: p. 1821.

72. Barnett, M.R. and Stanford, N., Influence of microstructure on strain distribution in Mg-3Al-1Zn. Scripta Materialia, 2007. 57: p. 1125.
73. del Valle, J.A., Carreno, F. and Ruano, O.A., Influence of texture and grain size on work hardening and ductility in magnesium-based alloys processed by ECAP and Rolling. Acta Materialia, 2006. 54: p. 4247.
74. Beer, A.G. and Barnett, M.R., Influence of initial microstructure on the hot working flow stress of Mg-3Al-1Zn. Materials Science and Engineering A, 2006. 423: p. 292.
75. Barnett, M.R., Influence of deformation condition and texture on the high temperature flow stress of magnesium AZ31. Jounal of Light Metals, 2001. 1: p. 167.
76. Choi, S.H., Shin, E.J. and Seong, B.S., Simulation of deformation twins and deformation texture in an AZ31 Mg alloy under uniaxial compression. Acta Materialia, 2007. 55: p. 4181.
77. Jain, A. and Agnew, S.R., Modeling the temperature dependent effect of twinning on the behavior of magnesium alloy AZ31B sheet. Materials Science and Engineering A, 2007. 462: p. 29.
78. Jiang, J., Godfrey, A, Liu, W and Liu, Q., Microtexture evolution via deformation twinning and slip during compression of magnesium alloy AZ31. Materials Science and Engineering A, 2008. 483: p. 576.
79. Yukutake, E., Kaneko, J. and Sugamata, M., Anisotropy and non-uniformity in plastic behavior of AZ31 magnesium alloy plates. Materials Transactions, 2003. 44: p. 452.


80. Kelley, E.W. and Hosford, W.F,. Plane-strain compression of magnesium and magnesium alloy crystals. Transactions of AIME, 1968. 242: p. 5.
81. Jiang, J., Godfrey, A. and Liu, Q., Influence of grain orientation on twinning during warm compression of wrought Mg-3Al-1Zn. Materials Science and Technology, 2005. 21: p. 1417.
82. Ernst, T. and Laves, F., The deformation of magmesium and its alloys. Z. Metallk., 1949. 40: p. 1.
83. Couling, S.L., Pashak, J.F., and Sturkey, L., Unique deformation and aging characteristics of certain magnesium alloys. Transactions of AIME, 1959. 51: p. 94
84. Couling, S.L. and Pearsall, G.W., Determination of orientation in magnesium by polarized light examination. Transactions of AIME, 1957. 209: p. 939.
85. del Valle, J.A., Perez-Prado, M.T. and Ruano, O.A., Texture evolution during large-strain hot rolling of the Mg AZ61 alloy. Materials Science and Engineering A, 2003. 355: p. 68.
86. Bach, F.W., Behrens, B.A., Rodman, M., Rossberg. A. and Kurz, G., Macroscopic damage by the formation of shear bands during the rolling and deep drawing of magnesium sheets. JOM, 2005. 57: p. 57.
87. ASM Handbook. Properties and Selection: Nonferrpus Alloys and Special-Purpose Materials. 1990. Vol. 2.
88. Bay, B., Hansen, N., Hughes, D. and Kuhlmanwilsdorf, D., Evolution of FCC deformation structures in polyslip. Acta Metallurgica, 1992. 40: p. 205.