摩擦攪拌製程對Al-5Mg-0.6Mn合金而言具有可實施性且可提升其機械性質；然而，攪拌材中細小的再結晶組織在高溫下不安定，後續加熱誘發的粗大化現象對強度與延性將造成不良影響。本研究選用Al-5Mg-0.6Mn等軸晶鑄造材為研究用母材，對其施予摩擦攪拌與後續加熱處理。本研究將探討摩擦攪拌與後續加熱之微觀組織特徵對Al-5Mg-0.6Mn合金常溫拉伸性質的影響，並以Hall-Petch方程式(y+ kyd-1/2)討論拉伸降伏強度與晶粒徑間的關係。
摩擦攪拌造成的微觀組織細化可使攪拌材之介金屬化合物散佈強化效應、細晶強化效應與結晶方位強化效應均優於鑄造材，因而攪拌材強度高於鑄造材。攪拌材中細小且均勻的組織使拉伸過程中裂紋較不易生成且傳播較慢，因而攪拌材有較佳的拉伸延性。
迴轉速範圍介於450 rpm - 850 rpm時，提高迴轉速有助改善高溫安定性。低迴轉速攪拌材內部殘留應力高，後續加熱後容易觀察到晶粒組織的變化，溫度由100 ℃提高至400 ℃分別出現回復、晶粒溫和成長、再結晶與晶粒劇烈粗大化現象。加熱溫度達500 ℃，攪拌區晶粒則全面粗大化，該現象使常溫拉伸強度及延性明顯下降。
摩擦攪拌與後續加熱用以控制Al-5Mg-0.6Mn合金的晶粒尺度，以探討影響Hall-Petch方程式中與ky值的可能影響因素。摩擦攪拌及中溫後續加熱材皆具有微細的晶粒組織，兩者拉伸降伏強度與晶粒徑間的關係可用相同Hall-Petch方程式描述；高溫加熱粗晶材的兩個Hall-Petch常數均低於前者。實驗結果顯示粗晶材中結晶方位強化效應與晶界強化效應較低，此應分別為造成值與ky值小於細晶材的主導因素。

Friction stir process (FSP) and post-FSPed heating were carried out to Al-5Mg-0.6Mn cast sheet to investigate the effects of microstructural variation on the room-temperature tensile properties. Hall-Petch relation y = 0 + kyd-1/2 was used to examined the grain size dependence of tensile yield stress. Experimental data shows that microstructural refinement and homogenization can be achieved by FSP and that increase the tensile strength and ductility. However, thermal grain coarsening phenomenon extremely happens in the specimen friction- stirred at low rotational speed. Dramatic grain coarsening causes a deterioration of crystalline orientation strengthening effect and grain boundary rigidity, which leads to the decrease Hall-Petch parameters 0 and ky.

[1] J. E. Hatch, “Aluminum Properties and Physical Metallurgy”, ASM International, Ohio/USA, pp. 351-378, 2005.
[2] 王祝堂與田榮璋，『鋁合金及其加工手冊』，中南大學出版社，湖南省/中國，232-250頁，2000年。
[3] J. G. Kaufman, “Applications for Aluminum Alloys and Tempers”, ASM International, Ohio/USA, pp. 87-118, 2000.
[4] D. Lohwasser and Z. Chen, “Friction Stir Welding: From Basics to
Applications”, Woodhead Publishing Limited, Cambridge/UK, 2010.
[5] R. S. Mishra and M. W. Mahoney, “Friction Stir Welding and
Processing”, ASM International, Ohio/USA, 2007.
[6] Z. Y. Ma, Friction Stir Processing Technology: A Review, Metall.
Mater. Trans. A, vol. 39, pp. 642-658, 2008.
[7] S. Mironov, Y. S. Sato, H. Kokawa, H. Inoue and S. Tsuge, Structural Response of Superaustenitic Stainless Steel to Friction Stir Welding, Acta Mater., vol. 59, pp. 5472-5481, 2011.
[8] P. L. Threadgill, A. J. Leonard, H. R. Shercliff and P. J. Withers, Friction Stir Welding of Aluminium Alloys, Int. Mater. Rev., vol. 54, pp. 49-93, 2009.
[9] 陳思達，『純鋁及鋁銅合金拉伸性質之摩擦攪拌效應及Hollomon方程式適用性檢討』，國立成功大學材料科學及工程學系博士論文，2011年。
[10] S. H. C. Park, Y. S. Sato and H. Kokawa, Basal Plane Texture and Flow Pattern in Friction Stir Weld of a Magnesium Alloy, Mater. Trans. A, vol. 34A, pp. 987-994, 2003.
[11] 李信委，『摩擦攪拌製程對AZ31鎂合金擠型材微觀組織及拉伸性質之影響』，國立成功大學材料科學及工程學系博士論文，2011年。
[12] T. Sakthivel and J. Mukhopadhyay, Microstructure and Mechanical
Properties of Friction Stir Welded Copper, J. Mater. Sci., vol. 42, pp.
8126-8129, 2007.
[13] K. Surekha and A. E. Botes, Development of High Strength, High
Conductivity Copper by Friction Stir Processing, Mater. Des, vol. 32, pp. 911-916, 2011.
[14] S. Mironov, Y. Zhang, Y. S. Sato and H. Kokawa, Development of Grain Structure in β-phase Field during Friction Stir Welding of
Ti-6Al-4V Alloy, Scripta Mater., vol. 59, pp. 27-30, 2008.
[15] K. E. Knipling and R. W. Fonda, Texture Development in the Stir Zone of Near-α Titanium Friction Stir Welds, Scripta Mater., vol. 60,
pp. 1097-1100, 2009.
[16] K. A. A. Hassan, A. F. Norman, D. A. Price and P. B. Prangnell, Stability of Nugget Zone Grain Structures in High Strength Al-alloy Friction Stir Welds during Solution Treatment, Acta Mater., vol. 51, pp. 1923-1936, 2003.
[17] I. Charit and R. S. Mishra, Low Temperature Superplasticity in a
Friction-stir-processed Ultrafine Grained Al–Zn–Mg–Sc Alloy, Acta
Mater., vol. 53, pp. 4211-4223, 2005.
[18] E. Cerri and P. Leo, Influence of High Temperature Thermal Treatment on Grain Stability and Mechanical Properties of Medium Strength Aluminium Alloy Friction Stir Welds, J. Mater. Process.
Technol., vol. 213, pp. 75-83, 2013.
[19] Z. Zhang, B. L. Xiao and Z. Y. Ma, Influence of Post Weld Heat Treatment on Microstructure and Mechanical Properties of Friction stir-welded 2014 Al-T6 Alloy, Adv. Mater. Res., vol. 409, pp. 299- 304, 2011.
[20] T. Minton and J. Au, Stability of Friction Stir Welds at Superplastic Forming Temperatures, Key Eng. Mater., vol. 410-411, pp. 117-125, 2009.
[21] F. C. Liu, B. L. Xiao, K. Wang and Z. Y. Ma, Investigation of Superplasticity in Friction Stir Processed 2219 Al Alloy, Mater. Sci. Eng. A, vol. 527, pp. 4191-4196, 2010.
[22] Y. C. Chen, J. C. Feng and H. J. Liu, Stability of the Grain Structure
in 2219-O Aluminum Alloy Friction Stir Welds during Solution
Treatment, Mater. Charact., vol. 58, pp. 174-178, 2007.
[23] I. Charit and R. S. Mishra, High Strain Rate Superplasticity in a Commercial 2024 Al Alloy via Friction Stir Processing, Mater. Sci. Eng., vol. 359, pp. 290-296, 2003.
[24] E. Cerri and P. Leo, Mechanical Properties Evolution during Post-
welding-heat Treatments of Double-lap Friction Stir Welded Joints,
Mater. Des., vol. 32, pp. 3465-3475, 2011.
[25] X. G. Chen, M. D. Silva, P. Gougeon and L. St-Georges, Microstructure and Mechanical Properties of Friction Stir Welded AA6063-B4C Metal Matrix Composites, Mater. Sci. Eng. A, vol. 518, pp. 174-184, 2009.
[26] E. Cerri, Thermal Stability of Fine Grains as a Function of Process Parameters in FSW Butt Joints, Mater. Sci. Forum, vol. 683, pp. 249-254, 2011.
[27] S. Mironov, K. Masaki, Y. S. Sato and H. Kokawa, Texture Produced by Abnormal Grain Growth in Friction Stir-welded Aluminum Alloy 1050, Metall. Mater. Trans. A, vol. 44A, pp. 1153-1157, 2013.
[28] K. Chen, W. Gan, K. Okamoto, K. Chung and R. H. Wagoner, The Mechanism of Grain Coarsening in Friction-stir-welded AA5083 after Heat Treatment, Metall. Mater. Trans. A, vol. 42, pp. 488-507, 2011.
[29] I. Charit and R. S. Mishra, Abnormal Grain Growth in Friction Stir
Processed Alloys, Scripta Mater., vol. 58, pp. 367-371, 2008.
[30] S. Mironov, Y. Motohashi and R. Kaibyshev, Grain Growth Behaviors
in a Friction-stir-welded ZK60 Magnesium Alloy, Mater. Trans., JIM,
vol. 48, pp. 1387-1395, 2007.
[31] H. Yoshioka, S. Fukumoto, A. Yamamoto, H. Tsubakino, K. Okita and T. Tomita, Effect of Post Weld Heat Treatment on Mechanical Properties and Microstructures of Friction Stir Welded AZ31B Magnesium Alloy, J. Jpn. I. Met., vol. 58, pp. 2-7, 2008.
[32] M. M. Attallah, C. L. Davis and M. Strangwood, Microstructure-
Microhardness Relationships in Friction Stir Welded AA5251, J.
Mater. Sci., vol. 42, pp. 7299-7306, 2007.
[33] Y. S. Sato, S. H. C. Park and H. Kokawa, Microstructural Factors
Governing Hardness in Friction-stir Welds of Solid-solution-hardened
Al Alloys, Metall. Mater. Trans. A, vol. 32A, pp. 3033-3042, 2001.
[34] Y. S. Sato, M. Urata, H. Kokawa and K. Ikeda, Hall-Petch Relationship in Friction Stir Welds of Equal Channel Angular-pressed Aluminium Alloys, Mater. Sci. Eng. A, vol. 354, pp. 298-305, 2003.
[35] T. Hirata, T. Oguri, H. Hagino, T. Tanaka, S. W. Chung, Y. Takigawa and K. Higashi, Influence of Friction Stir Welding Parameters on Grain Size and Formability in 5083 Aluminum Alloy, Mater. Sci. Eng. A, vol. 456, pp. 344-349, 2007.
[36] G. R. Cui, Z. Y. Ma and S. X. Li, The Origin of Non-uniform
Microstructure and its Effects on the Mechanical Properties of a
Friction Stir Processed Al-Mg Alloy, Acta Mater., vol. 57, pp.
5718-5729, 2009.
[37] 黃國聰，『鋁-鎂合金拉伸與振動破壞特性之摩擦攪拌效應研究』，
國立成功大學材料科學及工程學系博士論文，2008年。
[38] H. Baker and H. Okamoto, “ASM Handbook: Alloy Phase Diagrams”, ASM International, Ohio/USA, pp. 278-335, 1992.
[39] A. Shukla and A. D. Pelton, Thermodynamic Assessment of the Al- Mn and Mg-Al-Mn Systems, J. Phase Equilib. Diff., vol. 30, pp. 28- 39, 2008.
[40] D. L. Olson, T. A. Siewert, S. Liu and G. R. Edwards, “ASM Handbook: Welding, Brazing and Soldering”, ASM International, Ohio/USA, pp. 175-291, 1993.
[41] J. R. Kissell and R. L. Ferry, “Aluminum Structure: A Guide to their
Specifications and Design”, John Wiley & Sons, INC, New York/ USA, pp. 289-306, 2002.
[42] H. Fujii, L. Cui, M. Maeda and K. Nogi, Effect of Tool Shape on Mechanical Properties and Microstructure of Friction Stir Welded Aluminum Alloys, Mater. Sci. Eng. A, vol. 419, pp. 27-33, 2006.
[43] T. Hirata, T. Oguri, H. Hagino, T. Tanaka, S. W. Chung, Y. Takigawa
and K. Higashi, Influence of Friction Stir Welding Parameters on
Grain Size and Formability in 5083 Aluminum Alloy, Mater. Sci.
Eng. A, vol. 456, pp. 344-349, 2007.
[44] S. Hong, S. Kim, C. G. Lee and S. J. Kim, Fatigue Crack Propagation
Behavior of Friction Stir Welded 5083-H32 Al Alloy, J. Mater. Sci.,
vol. 42, pp. 9888-9893, 2007.
[45] Y. S. Sato, Y. Sugiura, Y. Shoji, S. H. C. Park, H. Kokawa and K.
Ikeda, Post-weld Formability of Friction Stir Welded Al Alloy 5052,
Mater. Sci. Eng. A, vol. 369, pp. 138-145, 2004.
[46] T. S. Mahmoud, A. M. Gaafer and T. A. Khalifa, Effect of Tool
Rotational and Welding Speeds on Microstructural and Mechanical
Characteristics of Friction Stir Welded A319 Cast Al Alloy, Mater.
Sci. Technol., vol. 24, pp. 553-559, 2008.
[47] Z. Y. Ma, S. R. Sharma and R. S. Mishra, Effect of Friction Stir
Processing on the Microstructure of Cast A356 Aluminum, Mater.
Sci. Eng. A, vol. 433, pp. 269-278, 2006.
[48] W. B. Lee, Y. M. Yeon and S. B. Jung, The Improvement of
Mechanical Properties of Friction-stir-welded A356 Al Alloy,
Mater. Sci. Eng. A, vol. 355, pp. 154-159, 2003.
[49] S. Benavides, Y. Li, L. E. Murr, D. Brown and J. C. McClure,
Low-temperature Friction-stir Welding of 2024 Aluminum, Scripta
Mater., vol. 41, pp. 809-814, 1999.
[50] M. A. Safarkhanian, M. Goodarzi and S. M. A. Boutorabi, Effect of Abnormal Grain Growth on Tensile Strength of Al-Cu-Mg Alloy Friction Stir Welded Joints, J. Mater. Sci., vol. 44, pp. 5452-5458, 2009.
[51] G. Liu, L. E. Murr, C. S. Niou, J. C. McClure and F. R. Vega,
Microstructural Aspects of the Friction-stir Welding of 6061-T6
Aluminum, Scripta Mater., vol. 37, pp. 355-361, 1997.
[52] Y. S. Sato, H. Kokawa, M. Enomoto, S. Jogan and T. Hashimoto,
Precipitation Sequence in Friction Stir Weld of 6063 Aluminum
during Aging, Metall. Mater. Trans. A, vol. 30A, pp. 3125-3130,
1999.
[53] M. W. Mahoney, C. G. Rhodes, J. G. Flintoff, R. A. Spurling and
W. H. Bingel, Properties of Friction-stir-welded 7075 T651
Aluminum, Metall. Mater. Trans. A, vol. 29A, pp. 1955-1964, 1998.
[54] 黃展鴻，『摩擦攪拌7075鋁合金組織特性及拉伸性質之後熱處理效應探討』，國立成功大學材料科學及工程學系碩士論文，2007年。
[55] E. O. Hall, The Deformation and Ageing of Mild Steel III Discussion
of Results, Proc. Phys. Soc. B, vol. 64, pp. 747- 753, 1951.
[56] N. J. Petch, The Cleavage Strength of Polycrystals, J. Iron Steel I.,
vol. 173, pp. 25-28, 1953.
[57] R. Armstrong, I. Codd, R. M. Douthwaite and N. J. Petch, The
Plastic Deformation of Polycrystalline Aggregates, Philos. Mag.,
vol. 7, pp. 45-58, 1962.
[58] G. Bhargava, W. Yuan, S. S. Webb and R. S. Mishra, Influence of Texture on Mechanical Behavior of Friction-stir-processed Magnesium Alloy, Metall. Mater. Trans. A, vol. 41A, pp. 13-17,
2009.
[59] Y. N. Wang, C. I. Chang, C. J. Lee, H. K. Lin and J. C. Huang, Texture and Weak Grain Size Dependence in Friction Stir Processed Mg-Al-Zn Alloy, Scripta Mater., vol. 55, pp. 637-640, 2006.
[60]
Y. S. Sato, H. Kokawa, K. Ikeda, M. Enomoto, S. Jogan and T. Hashimoto, Microtexture in the Friction-stir Weld of an Aluminum Alloy, Metall. Mater. Trans. A, vol. 32A, pp. 941-948, 2001.
[61] D. P. Field, T. W. Nelson, Y. Hovanski and K. V. Jata, Heterogeneity of Crystallographic Texture in Friction Stir Welds of Aluminum, Metall. Mater. Trans. A, vol. 32A, pp. 2869-2877, 2001.
[62]
P. B. Prangnell and C. P. Heason, Grain Structure Formation during Friction Stir Welding Observed by the Stop Action Technique,
Acta Mater., vol. 53, pp. 3179-3192, 2005.
[63] R. W. Fonda, K. E. Knipling and J. F. Bingert, Microstructural Evolution ahead of the Tool in Aluminum Friction Stir Welds, Scripta Mater., vol. 58, pp. 343-348, 2008.
[64] U. F. H. R. Suhuddin, S. Mironov, Y. S. Sato and H. Kokawa, Grain Structure and Texture Evolution during Friction Stir Welding of Thin
6016 Aluminum Alloy Sheets, Mater. Sci. Eng. A, vol. 527, pp. 1962- 1969, 2010.
[65] R. W. Fonda and K. E. Knipling, Texture Development in Friction Stir Welds. Sci. Technol. Weld. Join., vol. 16, pp. 288-294, 2011.
[66] W. Woo, H. Choo, D. Brown, S. Vogel, P. Liaw and Z. Feng, Texture Analysis of a Friction Stir Processed 6061-T6 Aluminum Alloy Using Neutron Diffraction, Acta Mater., vol. 54, pp. 3871-3882, 2006.
[67]
莊凱傑，『摩擦攪拌製程對AZ31鎂合金拉伸及振動破壞特性影響之研究』，國立成功大學材料科學及工程學系碩士論文，2007年。
[68] F. Montheillet, P. Gilormini and J. J. Jonas, Relation between Axial Stresses and Texture Development during Torsion Testing: A
Simplified Theory, Acta Metall., vol. 33, pp. 705-727, 1985.
[69] L. S. Toth, K. W. Neale and J. J. Jonas, Stress Response and Persistence Characteristics of the Ideal Orientations of Shear
Textures, Acta Metall., vol. 37, pp. 2197-2210, 1989.
[70] F. Montheillet, M. Cohen and J. J. Jonas, Axial Stresses and Texture Development during the Torsion Testing of Al, Cu and alpha-Fe,
Acta Metall., vol. 32, pp. 2077-2089, 1984.
[71] J. G. Sevillano, P. V. Houtte and E. Aernoudt, Contribution of Macroscopic Shear Bands to the Rolling Texture of FCC Metals, Scripta Mater., vol. 11, pp. 581-585, 1977.
[72] Y. S. Sato and H. Kokawa, Distribution of Tensile Property and Microstructure in Friction Stir Weld of 6063 Aluminum, Metall.
Mater. Trans. A, vol. 32A, pp. 3023-3031, 2000.
[73] G. I. Taylor, Analysis of Plastic Strain in a Cubic Crystal, Stephen Timoshenko 60th Anniversary Volume, pp. 218-224, 1938.
[74] P. Cotterill and P. R. Mould, “Recrystallization and Grain Growth in
Metals”, John Wiley and Sons Inc., New York/USA, pp. 266-325,
1996.
[75] F. J. Humphreys and M. Hatherly, “Recrystallization and Related
Annealing Phenomena”, Elsevier Science Ltd., Oxford/UK, pp. 315- 525, 2004.
[76] N. Rouag, G. Vigna and R. Penelle, Evolution of Local Texture and
Grain Boundary Characteristics during Secondary Recrystallisation of
Fe-3% Si Sheets, Acta Metall. Mater., vol. 38, pp. 1101-1107, 1990.
[77] C. V. Thompson, Experimental and Theoretical Aspects of Grain
Growth in Thin Films, Mater. Sci. Forum, vol. 94-96, pp. 245-258,
1992.
[78] P. A. Beck and H. Hu, Annealing Texture in Rolled Face Centered
Cubic Metals, J. Met., vol. 4, pp. 83-90, 1952.
[79] A. D. Rollett, D. J. Srolovitz and M. P. Anderson, Simulation and
Theory of Abnormal Grain Growth - Anisotropic Grain Boundary
Energies and Mobilities, Acta Metall., vol. 37, pp. 1227-1240, 1989.
[80] J. Dennis, P. S. Bate and F. J. Humphreys, Abnormal Grain Growth in
Metals, Mater. Sci. Forum, vol. 558-559, pp. 717-722, 2007.
[81] T. Gladman, Second Phase Particle Distribution and Secondary
Recrystallisation, Scripta Metall. Mater., vol. 27, pp. 1569-1573,
1992.
[82] T. Gladman, Abnormal Grain Growth during the Heat Treatment of
Steel, Mater. Sci. Forum, vol. 94-96, pp. 113-128, 1992.
[83] F. J. Humphreys, Unified Theory of Recovery, Recrystallization and
Grain Growth, Based on the Stability and Growth of Cellular
Microstructures II - The Effect of Second-phase Particles, Acta Mater., vol. 45, pp. 5031-5039, 1997.
[84] J. E. May and D. Turnbull, Secondary Recrystallization in Silicon
Iron, Trans. Metall. Soc. AIME, vol. 212, pp. 769-781, 1958.
[85] P. R. Rios, A Theory for Grain Boundary Pinning by Particles, Acta
Metall., vol. 35, pp. 2805-2814, 1987.
[86] Y. S. Sato, H. Watanabe and H. Kokawa, Grain Growth Phenomena in Friction Stir Welded 1100 Al during Post-weld Heat Treatment,
Sci. Technol. Weld. Join., vol. 12, pp. 318-323, 2007.
[87] T. Shibayanagi, M. Maeda and M. Naka, Microstructure and its High Temperature Stability in a Friction Stir Processed 5083 Aluminum Alloy, J. JPN. I. MET., vol. 56, pp. 347-353, 2006.
[88] F. C. Liu, Z. Y. Ma and L. Q. Chen, Low-temperature Superplasticity
of Al-Mg-Sc Alloy Produced by Friction Stir Processing. Scripta
Mater., vol. 60, pp. 968-971, 2009.
[89] A. Turnbull and E. R. D. Rios, The Effect of Grain Size, Strain and
Temperature on the Monotonic Stress-Strain Behaviour of
Polycrystalline Aluminium and Al alloys, Fatigue Fract. Eng.
Mater. Struc., vol. 18, pp. 1343-1354, 1995.
[90] R. W. Armstrong, “Yield, Flow and Fracture of Polycrystals”, Applied Science Publishers, Barking/UK, pp. 1-13, 1983.
[91] M. F. Ashby and D. R. H. Jones, “Engineering Materials 1: An
Introduction to their Properties and Applications”, Butterworth-
Heinemann, Oxford/UK, pp. 111-118, 1996.
[92] N. Hansen, The Effect of Grain Size and Strain on the Tensile Flow
Stress of Aluminium at Room Temperature, Acta Metall., vol. 25, pp.
863-869, 1977.
[93] H. Fujita and T. Tabata, The Effect of Grain Size and Deformation
Sub-structure on Mechanical Properties of Polycrystalline Aluminum,
Acta Metall., vol. 21, pp. 355-365, 1973.
[94] K. J. Kim, D. Y. Yang and J. W. Yoon, Microstructural Evolution and
its Effect on Mechanical Properties of Commercially Pure Aluminum
Deformed by ECAE (Equal Channel Angular Extrusion) via Routes A
and C. Mater. Sci. Eng. A, vol. 527, pp. 7927-7930, 2010.
[95] A. Niikura and Y. Bekki, Refinement of Recrystallized Grains in Al-
Mg Alloys Induced by Super-high-reduction Rolling and Consequent
Annealing, Mater. Sci. Forum, vol. 331-337, pp. 871-878, 2000.
[96] T. D. Topping, B. Ahn, Y. Li, S. R. Nutt and E. J. Lavernia,
Influence of Process Parameters on the Mechanical Behavior of an
Ultrafine-grained Al Alloy, Metall. Mater. Trans. A, vol. 43, pp. 505-
519, 2011.
[97] E. Schmid and W. Boas, “Plasticity of Crystals”, F. A. Hughes & Co. Limited, London/UK, 1950.
[98] R. E. Reed-Hill, “Inhomogeneity of Plastic Deformation”, ASM International, Ohio/USA, 1973.
[99] J. F. W. Bishop and R. Hill, A Theory of the Plastic Distortion of a
Polycrystalline Aggregate under Combined Stresses, Philos. Mag.,
vol. 42, pp. 414-417, 1951.
[100] J. F. W. Bishop and R. Hill, A Theoretical Derivation of the Plastic
Properties of a Polycrystalline Face-centred Metal, Philos. Mag.,
vol. 42, pp. 1298-1307, 1951.
[101] G. Y. Chin and W. L. Mammel, Computer Solutions of the Taylor
Analysis for Axisymmetric Flow, Trans. Metall. Soc. AIME, vol. 239
, pp. 1400-1405, 1967.
[102] G. I. Taylor, Plastic Strain in Metals, J. I. Met., vol. 62, pp. 307-324,
1938.
[103] J. M. Robinson and M. P. Shaw, Microstructural and Mechanical Influences on Dynamic Strain Aging Phenomena, Int. Mater. Rev., vol. 39, pp. 113-122, 1994.
[104] P. Rodriguez, Serrated Plastic Flow, Bull. Mater. Sci., vol. 6, pp. 653-663, 1984.
[105] A. Yilmaz, The Portevin–Le Chatelier Effect: A Review of Experimental Findings, Sci. Technol. Adv. Mater., vol. 12, pp. 063001-063016, 2001.
[106] Y. Bergström and W. Roberts, A Dislocation Model for Dynamical Strain Ageing of α-Iron in the Jerky-flow Region, Acta Metall., vol. 19, pp. 1243-1251, 1971.
[107] D. J. Dingley and D. McLean, Components of the Flow Stress of Iron, Acta Metall., vol. 15, pp. 885-901, 1967.
[108] F. L. Châtelier, Influence du Temps et de la Temperature sur les Essais
au Choc, Revue de métallurgie, vol. 6, pp. 914-917, 1909.
[109] F. L. Châtelier and A. Portevin, Sur le Phénomène Observé lors de
l’essai de Traction d’alliages en Cours de Transformation, C. R. Acad.
Sci. Paris, vol. 176, pp. 507-510, 1923.
[110] K. Chihab, Y. Estrin, L. P. Kubin and J. Vergnol, The Kinetics of the Portevin-Le Chatelier Bands in an Al-5 at.% Mg Alloy, Scripta Metall., vol. 21, pp. 203-208, 1987.
[111] W. Wen and J. G. Morris, An Investigation of Serrated Yielding in 5000 Series Aluminum Alloys, Mater. Sci. Eng. A, vol. 354, pp. 279-285, 2003.
[112] 陳銘欽，『置換型面心立方固溶合金應變時效之理論探討與鋁-鎂合金應變時效實驗』，國立成功大學礦冶及材料科學研究所博士論文，1993年。
[113] H. Dierke, F. Krawehl, S. Graff, S. Forest, J. Šachl and H. Neuhäuser, Portevin-LeChatelier Effect in Al-Mg Alloys: Influence of Obstacles- Experiments and Modelling, Comp. Mater. Sci., vol. 39, pp. 106-112, 2007.
[114] J. Kang, R. K. Mishra, D. S. Wilkinson and O. S. Hopperstad, Effect of Mg Content on Portevin-Le Chatelier Band Strain in Al-Mg Sheet Alloys, Phil. Mag. Lett., vol. 92, pp. 647-655, 2012.
[115] B. J. Brindley and P. J. Worthington, Serrated Yielding in Aluminium -3% Magnesium, Acta Metall., vol. 17, pp. 1357-1361, 1969.
[116] M. Lebyodkin, L. Dunin-BarkowskⅡ, Y. Brechet, Y. Estrin and L. P. Kubin, Spatio-temporal Dynamics of the Portevin-Le Chatelier Effect Experiment and Modelling, Acta Mater., vol. 48, pp. 2529-2541, 2000.
[117] W. Wen and J. G. Morris, The Effect of Cold Rolling and Annealing on the Serrated Yielding Phenomenon of AA5182 Aluminum Alloy, Mater. Sci. Eng. A, vol. 373, pp. 204-216, 2004.
[118] J. M. Robinson and M. P. Shaw, Observations on Deformation Characteristics and Microstructure in an Al-Mg Alloy during Serrated Flow, Mater. Sci. Eng. A, vol. 174, pp. 1-7, 1994.
[119] G. Horváth, N. Q. Chinh, J. Gubicza and J. Lendvai, Plastic Instabilities and Dislocation Densities during Plastic Deformation in Al-Mg Alloy, Mater. Sci. Eng. A, vol. 445-446, pp. 186-192, 2007.
[120] K. Chihab and C. Fressengeas, Time Distribution of Stress Drops, Critical Strain and Crossover in the Dynamics of Jerky Flow, Mater. Sci. Eng. A, vol. 356, pp. 102-107, 2003.
[121] Y. Estrin and M. A. Lebyodkin, The Influence of Dispersion Particles on the Portevin-Le Chatelier Effect: from Average Particle Characteristics to Particle Arrangement, Mater. Sci. Eng. A, vol. 387-389, pp. 195-198, 2004.
[122] H. Sheikh, Investigation into Characteristics of Portevin-Le Chatelier Effect of an Al-Mg Alloy, J. Mater. Eng. Perform., vol. 19, pp. 1264-1267, 2010.
[123] 徐明堅，『粗大硬質第二相對鋁合金動態應變時效影響之研究』，國立成功大學礦冶及材料科學研究所碩士論文，1992年。
[124] 許耿榮，『鋁-矽合金之動態應變時效效應探討』，國立成功大學礦冶及材料科學研究所碩士論文，1991年。
[125] 陳錦修，『兩相共晶鋁合金213K至673K之拉伸特性研究』，國立成功大學礦冶及材料科學研究所博士論文，1996年。
[126] A. H. Cottrell, A note on the Portevin-Le Chatelier Effect, Phil. Mag. vol. 44, pp. 829-832, 1953.
[127] A. H. Cottrell and M. A. Jaswon, Distribution of Solute Atoms Round a Slow Dislocation, P. Roy. Soc. Lond, A Mat. vol. 199, pp. 104-114, 1949.
[128] P. M. Yushkevich, L. V. Manankova and V. E. Stepanovich, Blue Brittleness of Steel, Met. Sci. Heat Treat., vol. 16, pp. 344-345, 1974.
[129] ASTM E112-12:2012, Standard Test Methods for Determining Average Grain Size.
[130] ISO 4499:1978, Hardmetals－Metallographic Determination of Microstructure.
[131] V. Randle, “The Role of the Coincidence Site Lattice in Grain
Boundary Engineering”, Institute of Materials, London/UK, 1996.
[132] H. J. Bunge, “Texture Analysis in Materials Science: Mathematical
Methods”, Butterworth, London/UK, 1982.
[133] I. S. Kim and M. C. Chaturvedi, Serrated Flow in Al-5%Mg Alloy,
Mater. Sci. Eng., vol. 37, pp. 165-172, 1979.
[134] E. Pink and A. Grinberg, Stress Drop in Serrated Flow Curves of Al5Mg, Acta Metall., vol. 30, pp. 2153-2163, 1982.
[135] N. Chawla and Y. L. Shen, Mechanical Behavior of Particle Reinforced Metal Matrix Composites, Adv. Eng. Mater, vol. 3, pp. 357-370, 2001.
[136] R. Chang, W. L. Morris and O. Buck, Fatigue Crack Nucleation at Intermetallic Particles in Alloys- A Dislocation Pile-up Model, Scripta Metall., vol. 13, pp. 191-194, 1979.
[137] P. Mummery and B. Derby, The Influence of Microstructure on the Fracture Behaviour of Particulate Metal Matrix Composites, Mater. Sci. Eng. A, vol. 135, pp. 221-224, 1991.
[138] D. J. Lloyd, Partice Reforced Aluminum and Magnesium Matrix Composites, Int. Mater. Rev., vol. 39, pp. 1-23, 1994.
[139] H. Tada, P. C. Paris and G. R. Irwin, “The Stress Analysis of Cracks Handbook”, ASME Press, New York/USA, 2000.
[140] S. A. Khodir, T. Shibayanagi and M. Naka, Control of Hardness Distribution in Friction Stir Welded AA2024-T3 Aluminum Alloy, Mater. Trans., JIM, vol. 47, pp. 1560-1567, 2006.
[141] W. Tang, X. Guo, J. C. McClure, L. E. Murr and A. Nunes, Heat Input and Temperature Distribution in Friction Stir Welding, J. Mater. Process Manu. Sci., vol. 7, pp. 163-172,1998.
[142] H. Rezaei, M. H. Mirbeik and H. Bisadi, Effect of Rotational Speeds on Microstructure and Mechanical Properties of Friction-stir-welded 7075-T6 Aluminium Alloy, J. Mech. Eng. Sci., vol. 225, pp. 1761- 1773, 2011.
[143] F. C. Liu and Z. Y. Ma, Influence of Tool Dimension and Welding Parameters on Microstructure and Mechanical Properties of Friction- stir-welded 6061-T651 Aluminum Alloy, Metall. Mater. Trans. A, vol. 39, pp. 2378-2388, 2008.
[144] M. Imam, K. Biswas and V. Racherla, On Use of Weld Zone Temperatures for online Monitoring of Weld Quality in Friction Stir Welding of Naturally Aged Aluminium alloys, Mater. Des., vol. 52, pp. 730-739, 2013.
[145] Ø. Frigaard, Ø. Grong and O. T. Midling, A Process Model for Friction Stir Welding of Age Hardening Aluminum Alloys, Metall. Mater. Trans. A, vol. 32A, pp. 1189-1200, 2000.
[146] Y. J. Kwon, N. Saito and I. Shigematsu, Friction Stir Process as a New Manufacturing Technique of Ultrafine-grained Aluminum Alloy, J. Mater. Sci. Lett., vol. 21, pp. 1473-1476, 2002.
[147] N. Rajamanickam, V. Balusamy, G. M. Reddy and K. Natarajan, Effect of Process Parameters on Thermal History and Mechanical Properties of Friction Stir Welds, Mater. Des., vol. 30, pp. 2726-2731, 2009.
[148] Y. S. Sato, M. Urata and H. Kokawa, Parameters Controlling Microstructure and Hardness during Friction-stir Welding of Precipitation-hardenable Aluminum Alloy 6063, Metall. Mater. Trans.
A, vol. 33A, pp. 625-635, 2002.
[149] M. Selvaraj, V. Murali and S. R. K. Rao, Mechanism of Weld Formation during Friction Stir Welding of Aluminum Alloy, Mater.
Manu. Process, vol. 28, pp. 595-600, 2013.
[150] Z. L. Hu, X. S. Wang and S. J. Yuan, Quantitative Investigation of the Tensile Plastic Deformation Characteristic and Microstructure for Friction Stir Welded 2024 Aluminum Alloy, Mater. Charact., vol. 73, pp. 114-123, 2012.
[151] S. Park, Effect of Micro-texture on Fracture Location in Friction Stir Weld of Mg Alloy AZ61 during Tensile Test, Scripta Mater., vol. 49, pp. 161-166, 2003.
[152] J. Q. Su, T. W. Nelson, R. Mishra and M. Mahoney, Microstructural Investigation of Friction Stir Welded 7050-T651 Aluminium, Acta Mater., vol. 51, pp. 713-729, 2003.
[153] W. Xu, J. Liu and H. Zhu, A Study on the Hardness and Elastic Modulus of Friction Stir Welded Aluminum Alloy Thick Plate Joints Using Micro-indentation, J. Mater. Sci., vol. 46, pp. 1161-1166, 2010.
[154] V. Hauk, “Structural and Residual Stress Analysis by Nondestructive
Methods”, Elsevier Science, New York/USA, 1997.
[155] C. I. Chang, C. J. Lee and J. C. Huang, Relationship between Grain Size and Zener–Holloman Parameter during Friction Stir processing in AZ31 Mg Alloys, Scripta Mater., vol. 56, pp. 509-514, 2004.
[156] L. E. Murr, “Interfacial Phenomena in Metals and Alloys”, Addison-Wesley, Massachusetts/USA, 1975.
[157] S. Hong, S. Kim, C. Lee and S. Kim, Fatigue Crack Propagation Behavior of Friction Stir Welded Al-Mg-Si Alloy, Scripta Mater., vol. 55, pp. 1007-1010, 2006.
[158] H. Lombard, D. G. Hattingh, A. Steuwer and M. N. James, Effect of Process Parameters on the Residual Stresses in AA5083-H321 Friction Stir Welds, Mater. Sci. Eng. A, vol. 501, pp. 119-124, 2009.
[159] M. A. Sutton, A. P. Reynolds, D. Q. Wang and C. R. Hubbard, A Study of Residual Stresses and Microstructure in 2024-T3 Aluminum Friction Stir Butt Welds, J. Eng. Mater. Technol., vol. 124, pp. 215-221, 2002.
[160] K. Deplus, A. Simar, W. V. Haver and B. D. Meester, Residual Stresses in Aluminium Alloy Friction Stir Welds, I. J. Adv. Manu. Technol., vol. 56, pp. 493-504, 2011.
[161] H. Khodaverdizadeh, A. Mahmoudi, A. Heidarzadeh and E. Nazari, Effect of Friction Stir Welding (FSW) Parameters on Strain Hardening Behavior of Pure Copper Joints, Mater. Des., vol. 35, pp. 330-334, 2012.
[162] W. B. Lee, Y. M. Yeon and S. B. Jung, Mechanical Properties Related to Microstructural Variation of 6061 Al Alloy Joints by Friction Stir Welding, Mater. Trans., JIM, vol. 45, pp. 1700-1705, 2004.
[163] F. Zhou, X. Z. Liao, Y. T. Zhu, S. Dallek and E. J. Lavernia, Microstructural Evolution during Recovery and Recrystallization of a Nanocrystalline Al-Mg Alloy Prepared by Cryogenic Ball Milling, Acta Mater., vol. 51, pp. 2777-2791, 2003.
[164] J. W. Wyrzykowski and M. W. Grabski, The Hall-Petch Relation in Aluminium and its Dependence on the Grain Boundary Structure. Phil. Mag. A, pp. 505-520, 1986.
[165] N. Hansen, Hall-Petch Relation and Boundary Strengthening, Scripta Mater., pp. 801-806, 2004.
[166] J. P. Hirth, The Influence of Grain Boundaries on Mechanical Properties, Metall. Trans., vol. 3, pp. 3047-3067, 1972.
[167] J. B. McCombs, D. I. Golland and G. Mayer, The Effects of Crystallite Orientation and Size on the Strength of Polycrystals, Mater. Sci. Eng., vol. 15, pp. 275-282, 1974.
[168] P. Rodriguez, Grain Size Dependence of the Activation Parameters for Plastic Deformation: Influence of Crystal Structure, Slip System, and Rate-Controlling Dislocation Mechanism, Metall. Mater. Trans. A, pp.
2697-2705, 2004.