半固態製程中之SIMA製程擁有設備成本低、製程穩定且球化率佳的優點，本研究中採用一新型的二階段SIMA製程，省去了冷加工的步驟直接採用熱擠型導入足夠的應變能，並且加熱的方式改用鹽浴，讓材料更均勻受熱及縮短達到欲持溫溫度的時間。6xxx系列Al-Mg-Si合金為本研究所探討的材料，研究之目的為探討對Al-Mg-Si合金施以新型二階段SIMA製程後，Al-Mg-Si合金微觀組織演變與特徵、高溫成形性表現與變形機制、成形後的機械性質與沖蝕磨耗特性，以評估二階段新型SIMA製程之應用性。
微觀組織分析結果顯示，欲透過新型二階段SIMA製程獲得良好的球狀晶材料，必須具有足夠生成液相率的元素以及能夠細化球狀晶的元素，並需要適當的擠型條件，讓起始擠型材具有細小動態再結晶的組織。本研究中最適宜應用於SIMA製程的合金為6066鋁合金，具有足夠的Mg、Si和Cu元素以生成足夠的液相，並含有Mn元素促使球狀晶細化。研究結果證實液相率和球化率呈正相關，而擠型比不明顯影響球化率。此外，於新型SIMA製程中，球狀晶成長機制為Ostwald ripening。
高溫成形方面，本研究證實壓應力適用於SIMA材成形，但拉應力並不適合。高壓縮速率下，SIMA材可以表現出優於完全退火材與擠型材的高溫成形性，壓縮變形阻抗低且金屬材料流動性較佳。研究證實，高液相率的SIMA材壓縮變形阻抗較低，但球狀晶尺寸必須控制，如成長過大則會導致材料的高溫流動性下降。
機械性質的表現上，由於SIMA材中原先聚集於球狀晶晶界的硬脆低熔點第二相於高溫壓縮成形後的不再分佈於球狀晶晶界上，故材料不再呈現沿晶破壞，材料機械性質提高並具有大於20%的延性。而且壓縮成形後的SIMA材於T6人工時效熱處理後，元素均勻分佈並生成析出強化相，強度可顯著提高於420MPa以上，並擁有12%以上的延性，與一般T6材相近。
最後，研究發現，經由SIMA製程所得的硬質球狀晶晶界包覆軟質晶粒的組織，具有高於高硬度的T6材的低角度顆粒沖蝕磨耗阻抗。硬質的球狀晶晶界將成為軟質晶粒於低角度沖蝕時的保護屏障，提高材料低角度耐顆粒磨耗性質。

In this study, a new type and two-step SIMA process for Al-Mg-Si alloy were used. And the microstructural characteristics, high-temperture formability, mechanical properties and erosion properties were investigated. The high-hardness globular grain boundaries are formed by eutectic phases. This new type SIMA process was poved that it can decrease high-temperature compressive resistance and improve ability of metal flowing at high temperature. After SIMA forming process, the mechanical properties of materials can compete with common artificial aged materials. In addition, the oblique erosion resistance of Al-Mg-Si alloys also can be promoted by this new type SIMA process. All the results show that this SIMA process is a potential process.

1.N. Wang, Z. Zhou, and G. Lu, “Microstructural evolution of 6061 alloy during isothermal heat treatment”, Journal of Material Science & Technology, 27 (1), pp.8-14, 2011.
2.Z. Fan, “Semisolid metal processing”, International Materials Reviews, 47, pp.49-85, 2002.
3.Y. B. Song, K. T. Park, and C. P. Hong, “Recrystallization behavior of 7175 Al alloy during modified strain-induced melt-activation (SIMA) process”, Material Tranaction, 47, pp.1250-1256, 2006.
4.E. Parshizfard and S. G. Shabestari, “An investigation on the microstructural evolution and mechanical properties of A380 aluminum alloy during SIMA process”, Journal of Alloys and Compounds, 509, pp.9654-9658, 2011.
5.M. Paes and E. J. Zoqui, “Semi-solid behavior of new Al-Si-Mg alloy for thixoforming”, Materials Science and Engineering A, 406, pp.63-73, 2005.
6.ASM International Handbook Committee, “Properties and selection: nonferrous alloys and special-purpose materials” pp.51, 1990.
7.W. H. Cubberly, H. Baker, D. Benjamin, P. M. Unterweiser, C. W. Kirkpatrick, V. Knoll, and K. Nieman, “Properties and selection: nonferrous alloys and special-purpose materials”, American Society for Metals Handbook, 2, pp.118-119, 1986.
8.村上 陽太郎、龜井 清，「非鐵金屬材料學」，朝倉書店，76頁，1978。
9.J. E. Hatch, “Aluminum: properties and physical metallurgy”, American Society for Metals, pp.224-240, 1984.
10.G. E. Totten and D. S. Mackenzie, “Handbook of Aluminum-physical metallurgy and process”, Metal Dekker Inc., pp.168-185, 2003.
11.L. Zhen, W. D. Fei, S. B. Kang, and H. W. Kim, “Precipitation behavior of Al-Mg-Si alloys with high silicon content”, Journal of Materials Science, 32, pp.1895, 1997.
12.J. R. Davis, ”Aluminum and aluminum alloys”, ASM International, pp.90-92, 1993.
13.W. F. Miao and D. E. Laughlin, “Effects of Cu content and presaging on precipitation characteristics in Aluminum alloy 6022”, Metallurgical and Materials Transaction A, 31, pp.361-371, 2000.
14.J. Man, L. Jing, and S. G. Jie, “The effects of Cu addition on the microstructure and thermal stability of Al-Mg-Si alloy”, Journal of Alloys and Compounds, 437, pp.146-150, 2007.
15.P. Sepehrband, R. Mahmudi, and F. Khomamizadeh, “Effect of Zr addition on the aging behavior of A319 aluminum cast alloy”, Scripta Materialia, 52, pp.253-257, 2005.
16.D. J. Chakrabarti and D. E. Laughlin, “Phase relations and precipitation in Al-Mg-Si alloys with Cu additions”, Progress in Materials Science, 49, 99.389-410, 2004.
17.R. A. Jeniski Jr., “Effects of Cr addition on the microstructure and mechanical behavior of 6061-T6 continuously cast and rolled redraw rod”, Materials Science and Engineering A, 237, pp.52-64, 1997.
18.S. R. Claves, D. L. Elias, and W. Z. Misiolek, :Analysis of the intermetallic phase transformation occurring during homogenization of 6xxx aluminum alloys”, Materials Science Forum., 396, pp.667-674, 2002.
19.M. Cabibbo, E. Evangelista, C. Scalabroni, and E. Bonetti, “A transmission electron microscopy study of the role of Sc+Zr addition to a 6082-T8 alloy subjected to equal channel angular pressing”, Materials Science Forum., 503-504, pp.841-846, 2006.
20.梁達嵐，「改良式SIMA法製備鎂合金半固態成形胚料之研究」，國立交通大學機械工程學系，碩士論文，6-37頁，2007。
21.K. P. Young, C. P. Kyonka, and J. A. Courtois, United States Patent 4415374, Nov.15, 1983.
22.江俊憲，「高矽含量噴覆成型過共晶鋁矽合金之固態成形性與半固態製程研究」，國立成功大學材料科學及工程學系，博士論文，85頁，2005。
23.E. Tzimas, and A. Zavaliangos, “A comparative characterization of near-equiaxed microstructures as produced by spray casting, Magnetohydronamic casting and the stress induced, melt activated process”, Materials and Engineering A, 289, pp.217-227, 2000.
24.E. E. Glickman and M. Nathan, “On the kinetic mechanism of grain boundary wetting in metals”, Journal of Applied Physics, 85, pp.3185-3191, 1999.
25.Z. Wang, Z. Ji, M. Hu, and H. Xu, “Evolution of the semi-solid microstructure of ADC12 aaloy in a modified SIMA process”, Materials Characterization, 62, pp.925-930, 2011.
26.G. Yan, S. Zhao, S. Ma, and H. Shou, “Microstructural evolution of A356.2 alloy prepared by the SIMA process”, Materials Characterization, 69, pp.45-51, 2012.
27.A. Bolouri, M. Shahmiri, and C. G. Kang, “Study on the effect of the compression ratio and mushy zone heating on the thixotropic microstructure of AA7075 aluminum alloy via SIMA process”, Journal of Alloys and Compounds, 509, pp.402-408, 2011.
28.A. Bolouri, M. Shahmiri and C. G. Kang, “Coarsening of equiaxed microstructure in the semisolid state of aluminum 7075 alloy through SIMA processing”, Journal of Materials Science, 47, pp.3544-3553, 2012.
29.Y. B. Song, K. T. Park, and C. P Hong, “Grain refinement of 6061 Al alloy by the modified strain-induced melt-activated (SIMA) process for semi-solid processing”, Solid State Phenomena, 119, pp.311-314, 2007.
30.E. Tzimas and A. Zavaliangos, “Evolution of near-equizxed microstructure in the semisolid state”, Materials Science and Engineering A, 289, pp.228-240. 2000.
31.L. Zhangm Y. B. Liu, Z. Y. Cao, Y. F. Zhang and Q. Q. Zhang, “Effects of isothermal process parameters on the microstructure of semisolid AZ91D alloy produced by SIMA”, Journal of Materials Processing and Technology, 209, pp.792-797, 2009.
32.Q. D Qin, Y. G. Zhao, K. Xiu, W. Zhou, and Y. H. Liang, “Microstructure evolution of in situ Mg2Si/Al-Si-Cu composite in semisolid remelting process”, Materials Science and Engineering A, 407, pp.196-200, 2005.
33.Z. Ji, M. Hu, S. Suguyama, and J. Yanagimoto, “Formatioin process of AZ31B semi-solid microstructures through strain-induced melt activation method”, Materials Characterization, 59, pp.905-911, 2008.
34.J. G. Wang, P. Lu, H. Y. Wang, J. F. Liu, and Q. C. Jiang, “Semisolid microstructure evolution of the predeformed AZ91D alloy during heat treatment”, Journal of Alloys and Compounds, 395, pp.108-112, 2005.
35.S. C. Hardy and P. W. Voorhees, “Ostwald ripening in a system with a high volume fraction of coarsening phase”, Metallurgical Transactions A, 19, pp.2713-2721, 1988.
36.H. V. Atkinson and D. Liu, “Coarsening rate of microstructure in semi-solid aluminum alloys”, Transaction of Nonferrous Metals Society of China, 20, pp.1672-1676, 2010.
37.C. B. Alcock, “Thermochemical Processes: Principles and Models”, Reed Educational and Professional Publishing Ltd., pp.209-213, 2001.
38.木內學，「半熔融‧半凝固加工21世紀展望」，塑性加工，35，369頁，1994。
39.H. Yan and B. F. Zhou, “Thixotropic deformation behavior of semi-solid AZ61 magnesium alloy during compression process”, Materials Science and Engineering B, 132, pp.179-182, 2006.
40.E. Rabinowicz, Friction and wear of materials, 1965.
41.I. Finnie, “Some reflections on the past and future of erosion”, Wear, 186-187, pp.1-10, 1995.
42.A. Magnee, “Generalized law of erosion: application to various alloys and intermetallics” Wear, 181-183, pp.500-510, 1995.
43.I. Finnie, “Some observation on the erosion of ductile metals”, Wear, 19, pp.81-90, 1972.
44.J. G. A. Bitter, “A study of erosion phenomena: part I”, Wear, 6, pp.5-21, 1963.
45.J. G. A. Bitter, “A study of erosion phenomena: part II”, Wear, 6, pp.169-190, 1963.
46.I. Finnie, “Erosion of surfaces by solid particles”, Wear, 3, pp.87-103, 1960.
47.I. Finnie, J. Wolak, and Y. Kabil, “Erosion of metals by solid particles”, Journal of Materials, 2, pp.682-684, 1967.
48.G. P. Tilly and W. Sage, “The interaction of particle and material behavior in erosion processes”, Wear, 16, pp.447-465, 1970
49.S. K. Hovis, J. Talia, and R. O. Scattergood, “Erosion mechanisms in aluminum and Al-Si alloys”, Wear, 107, pp.175-181, 1986.
50.W. H. Jennings, W. J. Head, and C. R. Manning Jr, “A nechanistic model for the prediction of ductile erosion”, Wear, 40, pp.93-112, 1976.
51.H. Wensink and M. C. Elwenspoek, “A closer look at the ductile-brittle transition in solid particle erosion”, Wear, 253, pp.1035-1043, 2002.
52.K. H. Z. Gahr, “Wear by hard particles”, Tribology International, 31, pp.587-596, 1998.
53.H. Le Khac and P. G. Shewmon, “Effects of hardness on the solid particle erosion mechanisms in AISI 1060 steel”, Wear, 89, pp.291-302, 1983.
54.F. Y. Hung, L. H. Chen and T. S. Lui, “A study on erosion of upper bainitic ADI and PDI”, Wear, 260, pp.1003-1012, 2006.
55.Y. I. Oka, H. Ohnogi, T. Hosokawa, and M. Matsumura, “The impact angle dependence of erosion damage caused by solid particle impact”, Wear, 203-204, pp.573-579, 1997.
56.A. Levy, M. Aghazadeh, and G. Hickey, “The effect of test variables on the platelet mechanism of erosion”, Wear, 108, pp.23-41, 1986.
57.I. M. Hutchings, H. Baiyun, and H. Jiawen, “Erosion wear behavior and model of abradable seal coating”, Wear, 252, pp.9-15, 2002.
58.G. Sundararajan and P. G. Shewmon, “A new model for the erosion of metals at normal incidence”, Wear, 84, pp.237-258, 1983.
59.I. M. Hutchings, “A model for the erosion of metals by spherical particles at normal incidence”, Wera, 70, pp.269-281, 1981.
60.R. E. Winter and I. M. Hutchings, “The role of adiabatic shear in solid particle erosion”, Wear, 34, pp.141-148, 1975.
61.R. E. Winter and I M. Hutchings, “Solid particle erosion srudies using single angular particles”, Wear, 29, pp.181-194, 1974.
62.許益誌，「沃斯回火熱處理與球墨分佈對沃斯回火球墨鑄鐵沖蝕磨耗影響之探討」，國立成功大學材料科學及工程學系，碩士論文，1991。
63.S. Johansson, F. Ericson, and J. A. Schweitz, “Solid particle erosion – a statistical method for evaluation of strength properties of semiconducting materials”, Wear, 115, pp.107-120, 1987.
64.J. Zeng and T. J. Kim, “An erosion model of polycrystalline ceramics in abrasive waterjet cutting”, Wear, 193, pp.207-217, 1996.
65.J. L. Roubort, R. O. Scattergood, and A. P. L Turner, “The erosion of reaction-bonded Sic”, Wear, 59, pp.363-375, 1980.
66.K. Yildizli, M. B. Karamis, and F. Nair, “Erosion mechanisms of nodular and gray cast irons at different impact angles”, Wear, 261, pp.622-633, 2006.
67.E. E. Glickman and M. Nathan: Mater. Charact. 62 pp.925-930, 2011
68.J. E. Hatch: Aluminum: properties and physical metallurgy, ASM International, vol. 1, pp.50, 1984.
69.D. E. Laughlm and W. F. Miao, “The effect of Cu and Mn content and processingon precipitation hardening behavior in Al-Mg-Si-Cu alloy 6022”,The Mineral, Metals & Materials Society, pp.63-78, 1998.
70.L. F. Mondolfo: Aluminum alloys structure & properties, (1976) Chapter 4-3, pp.806-842.
71.H. J. Huang, Y. H. Cai, H. Cui, J. F. Huang, J. P. He and J. S. Zhabg, “Influence of Mn addition on microstructure and phase formation of spray-deposited Al-25Si-xFe-yMn alloy”, Material Science and Engineering A, 502, pp.118-125, 2009.
72.S. J. Hales and T. R. Mcnelley: Acta Matall. 36 (1998) 1229-1239.
73.Y. W. Shin, G. A. Sargent, and H. Conrad, “Effects of mmicrostructure on the erosion of Al-Si alloys by solid particles”, MTA, 18, pp.437-450, 1987.
74.劉中偉，「片狀石墨鑄鐵與鋁-矽系合金之矽砂沖蝕磨耗特性研究」，國立成功大學材料科學及工程學系，博士論文，1996年。
75.M. Elmagagli, T. Perry, and A. T. Alpas, “A parametric study of the relationship between microstructure and wear resistance of Al-Si alloys”, Wear, 262, pp.79-92, 2007.
76.J. P. Tu, J. Pan, M. Matsumura, and H. Fukunaga, “The solid particle erosion behavior of A118B4033 whisker-reinforced AC4C Al alloy matrix composites”, Wear, 223, pp.22-30, 1998.
77.D. P. Mondal, S. Das, A. K. Jha, and A. H. Yegneswaran, “Abrasive wear of Al alloy-Al203 particle composite: a study on the combined effect of load and size of abrasive”, Wear, 223, pp.131-138, 1998.
78.Y. Lwai, T. Honda, T. Miyajima, Y. Iwasaki, M. K. Surappa, and J. F. Xu, “Dry sliding wear behavior of Al2O3 fiber reinforced aluminum composites”, Composites Science and Technology, 60, pp.1781-1789, 2000.
79.F. Akhlaghi1 and A. H. S. Farhood, “Characterization of globular microstructure in NMS processed aluminum A356 alloy: the role of casting size”, Advenced Mateials Researchs, 264-265, pp.1868-1877, 2011.
80.M. Emamy, A. Razaghian and M. Karshenas, “The effect of strain-induced melt activation process on the microstructure and mechanical properties of Ti-refined A6070 Al alloy”, Materilas and Design, 46, pp.824-836, 2013.
81.K. S. Lee, S, Kim, K. R. Lim, S. H. Hing, K. B. Kim and Y. S. Na, ”Crystallization, High temperature defroemtaion behavior and solid-to-dolid formability of a Ti-based bulk metallic glass within supercooled liquid region”, Journal of Alloys and Compounds, 663, pp.270-278, 2016.
82.H. Tang, Z. Cheng, J. Liu and X. Ma, ”Preparation of a high strength Al-Cu-Mg alloy by mechanical alloying and press-forming”, Materials Science and Engineering A, 550, pp.51-54, 2012.
83.ASTM E112-12:2012, Standard Test Methods for Determining Average Grain Size.
84.ISO 4499:1975, Hard metals – Metallographic Determination of Microstructure.
85.R. A. Jeniski, “Effects of Cr Addition on the Microstructure and Mechanical Behavior of 6061-T6 Continuously Cast and Rolled Redraw Bar”, Materials Science and Engineering A, 237, pp.52-64, 1997.
86.ASM International Handbook Committee, “Alloy phase diagrams”, 1990.
87.W. J. Kim, S. H. Hong and J. H. Lee, “Superplasticity in PM 6061 Al alloy and elimination of strengthening effect by reinforcement in superplastic PM aluminum composites”, Materials Science and Engineering A, 298, pp.166-173, 2001.
88.E. O. Hall, “The deformation and aging of mild steel III”, Proceedongs of the Physical Society B, 64, pp.747-753, 1951.
89.N. J. Petch, “The cleavage strength of polycrystals”, Journal of Iron Steel Institute, 174, pp.8-25, 1953.
90.R. Armstrong, I. Codd, R. M. Douthwaite and N. J. Petch, “The plastic deformation of polycrystalline aggregates”, Philosophical Magazine 7, pp.45-58, 1962.
91.G. P. Tilly: Treatise on Materials Science and Technology, 13th ed., (D. Scott, Academic Press, New York, (1979), pp.287-319.
92.G. Timmermans and L. Froyen, “Fretting wear behaviour of hypereutectic P/M Al-Si in oil environment”, Wear, 230, pp.105-117, 1999.
93.L. Lasa and J. M. Rodriguez-Ibebe, “Effect of composition and processing route on the wear behavior of Al-Si alloys”, Scripta Materialia, 46, pp. 477-481, 2002.
94.J. W. Liou, T. S. Lui and L. H. Chen, “SiO2 particle erosion of A356.2 aluminum alloy and the related microstructural changes”, Wear, 211, pp.169-176, 1997.
95.C. W. Yang, Y. H. Chang, T. S. Lui and L. H. Chen, “Effect of friction stir processing and artificial peak aging on erosion resistance of Al-11Si-4Cu-2Ni-0.7Mg cast alloy”, Material and Design, 40, pp. 163-170, 2012.
96.Y. L. Saraswathi, S. Das and D. P. Mondal, “Influence of microstructure and experimental parameters on the erosion-corrosion behavior of Al alloy composites”, Materials Sceence and Engineering A, 425, pp.244-254, 2006.