本研究主要探討選區雷射重熔技術(SLM)製備之Al-10Si-Mg合金之微觀組織與機械性質及抗磨耗特性。SLM是將金屬粉末一層一層熔融堆疊而成的技術，由於雷射的瞬間高溫加熱使金屬粉末熔融再急冷凝固之Al-10Si-Mg會具極大溫度梯度而形成熔池(melting pool)晶胞微細結構，此細小晶粒會使材料有相較傳統鋁合金更高強度。
此研究比較兩組不同雷射參數(高雷射能量密度、低雷射能量密度)SLM試片之機械性質差異，並與4384鋁合金(Si:11.4 wt.%、Cu:3.2 wt.%、Ni:2.2 wt.%、Mg:0.8 wt.%)做比較，實驗顯示兩組SLM試片拉伸強度與硬度可達到4384傳統鋁合金T4T6熱處理條件。再者，SLM試片進行熱處理後，除了探討微觀組織變化，亦探討對於機械性質之影響。熱處理後SLM材中熔池晶胞微觀組織消失，取而代之是細小第二相析出在鋁基地中的微結構，熱處理後SLM材料硬度與拉伸強度皆有下降趨勢，延性則是上升。此外，高雷射能量密度3D-SLM材料經高溫拉伸試驗後發現在200°C環境下，仍具有200 MPa以上強度，顯示此3D-SLM材料可應用於熱環境。
兩組SLM材進行沖蝕磨耗測試，並對比T4T6處理4384鋁合金。實驗結果顯示，雷射參數為高雷射能量密度SLM試片抗沖蝕磨耗能力是優於4384-T4T6材料，3D-SLM製程Al-10Si-Mg合金具有高溫與磨耗工業應用潛力。

In order to demonstrate the credibility of SLM Al parts, their mechanical properties need to be studied.
The main goal of this research is to understand the microstructure, mechanical property, and erosion resistance property of Al-10Si-Mg alloy made by SLM technique. SLM technique is to stack metal powder after melting them. The high temperature of laser will melt metal powder and form melting pool, which is composed of fine grains. These fine grains have high mechanical strength compared to traditional Al alloy.
In this study, two laser parameters, high laser energy density and low laser energy, respectively, were chosen to fabricate samples. And we compare the mechanical properties of these samples with 4384 aluminum alloy. Result shows that the tensile strength and hardness of these samples made by two parameters are comparable with 4384 aluminum alloy, which is done by heat treatment.
Then, melting pool structure in SLM sample would disappear after heat treatment. Instead, fine Si particles would spread in Al matrix. This decreases the tensile strength and hardness of heat treated SLM samples while increases the ductility. Besides, SLM sample shows high temperature mechanical properties after tensile test at elevated temperature. Particle erosion test is conducted to compare 4384 aluminum alloy with samples of different laser parameters before and after heat treatment. The result shows that high laser energy density SLM sample has the best erosion resistance. In summary, high laser energy density sample shows great potential in high temperature erosion environment application.

1. M. Zeren, M., The effect of heat-treatment on aluminum-based piston alloys. Materials & Design, 28(9): p.p. 2511-2517, 2007.
2. J. Qiao, X. Liu, X. Liu, X. Bian, Relationship between microstructures and contents of Ca/P in near-eutectic Al–Si piston alloys. Materials Letters, 59(14-15): p.p. 1790-1794, 2005.
3. R. X. Li , R. D. Li, Y. H. Zhao, L. Z. He, C. X. Li, H. R. Guan, Z. Q. Hu, Age-hardening behavior of cast Al–Si base alloy. Materials Letters, 58(15): p.p. 2096-2101 , 2004.
4. 鄭敦文，摩擦攪拌改質對壓鑄鋁-14矽合金及肥粒體基2.9碳-2.5矽球墨鑄鐵之微觀組織演變及顆粒沖蝕磨耗行為之影響，國立成功大學材料科學及工程學系，博士論文，2012。
5. A. R. Farkoosh, M. Javidani, M. Hoseini, D. Larouche, M. Pekguleryuz, Phase formation in as-solidified and heat-treated Al–Si–Cu–Mg–Ni alloys: Thermodynamic assessment and experimental investigation for alloy design. Journal of Alloys and Compounds, 551: p.p. 596-606, 2013.
6. Y. Yang, Y. Li, W. Wu, D. Zhao, X. Liu, Evolution of nickel-rich phases in Al–Si–Cu–Ni–Mg piston alloys with different Cu additions. Materials & Design, 33: p.p. 220-225, 2012.
7. E. R. Wang, X. D. Hui, S. S. Wang, Y. F. Zhao, G. L. Chen, Improved mechanical properties in cast Al–Si alloys by combined alloying of Fe and Cu. Materials Science and Engineering: A, 527(29-30): p.p. 7878-7884, 2010.
8. Z. Ma, A.M. Samuel, F. H. Samuela, H. W. Doty, S. Valtierra, A study of tensile properties in Al–Si–Cu and Al–Si–Mg alloys: Effect of β-iron intermetallics and porosity. Materials Science and Engineering: A, 490(1-2): p.p. 36-51, 2008.
9. N. A. Belov, D. G. Eskin, N. N. Avxentieva, Constituent phase diagrams of the Al–Cu–Fe–Mg–Ni–Si system and their application to the analysis of aluminium piston alloys. Acta Materialia, 53(17): p.p. 4709-4722, 2005.
10. F. Toptan, A. C. Alves, I. Kerti, E. Ariza, L. A. Rocha, Corrosion and tribocorrosion behaviour of Al–Si–Cu–Mg alloy and its composites reinforced with B4C particles in 0.05M NaCl solution. Wear, 306(1-2): p.p. 27-35, 2013.
11. M. Warmuzek, Chemical composition of the Ni-containing intermetallic phases in the multicomponent Al alloys. Journal of Alloys and Compounds, 604: p.p. 245-252, 2014.
12. H. C. Chuang, T. S. Lui ,L. H. Chen, Characteristics and Effects of Particle Morphology and Tensile Ductility Resulting from FSP of Al-Si-Cu-Ni Casting and Forging Piston. Materials Transactions, 54(8): p.p. 1373-1380, 2013.
13. C. Yan, L. Hao, A. Hussein, P. Young, J. Huang, W. Zhu, Microstructure and mechanical properties of aluminium alloy cellular lattice structures manufactured by direct metal laser sintering. Materials Science & Engineering A 628: p.p. 238–246, 2015.
14. L. Thijs, K. Kempen, J. P. Kruth, J. V. Humbeeck, Fine-structured aluminium products with controllable texture by selective laser melting of pre-alloyed AlSi10Mg powder. Acta Materialia 61: p.p. 1809–1819, 2013.
15. N. T. Aboulkhair, C. Tuck, I. Ashcroft, I. Maskery, and N. Everitt, On the Precipitation Hardening of Selective Laser Melted AlSi10Mg. The Minerals, Metals & Materials Society and ASM International, 2015.
16. U. Tradowsky, J. White, R. M. Ward, N. Read, W. Reimers, M. M. Attallah, Selective laser melting of AlSi10Mg: Influence of post-processing on the microstructural and tensile properties development. Materials and Design 105: p.p. 212–222, 2016.
17. N. T. Aboulkhair, I. Maskery, C. Tuck, I. Ashcroft, N. M. Everitt, The microstructure and mechanical properties of selectively laser melted AlSi10Mg: The effect of a conventional T6-like heat treatment. Materials Science & Engineering A667: p.p. 139–146, 2016.
18. T. Furumoto, A. Koizumi, M. R. Alkahari, R. Anayama, A. Hosokawa, R. Tanaka, T. Ueda, Permeability and strength of a porous metal structure fabricated by additive manufacturing. Journal of Materials Processing Technology 219: p.p. 10–16, 2015.
19. X. Zhou, X. H. Liu, D. D. Zhang, Z. J. Shen, and W. Liu, Balling Phenomena in Selective Melted Tungsten, Journal of Materials Processing Technology, Vol. 222: p.p. 33-42, 2015.
20. H. Li, Q. Mao, Z. Wang, F. Miao, B. Fang, Z. Zheng, Enhancing mechanical properties of Al–Mg–Si–Cu sheets by solution treatment substituting for recrystallization annealing before the final cold-rolling. Materials Science and Engineering: A, 620: p.p. 204-212, 2015.
21. C. R. Brooks, Heat Treatment, Structure and Properties of Nonferrous Alloys, ASM : p.p. 18 and 106~114, 1992.
22. R. E. Winter and I. M. Hutchings, Solid particle erosion srudies using single angular particles, Wear, 29: p.p. 181-194, 1974.
23. 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。
24. F. Y. Hung, L. H. Chen and T. S. Lui, A study on erosion of upper bainitic ADI and PDI, Wear, 260: p.p. 1003-1012, 2006.
25. G. P. Tilly and W. Sage, The interaction of particle and material behavior in erosion processes, Wear, 16: p.p. 447-465, 1970.
26. K. Yildizli, M. B. Karamis, and F. Nair, Erosion mechanisms of nodular and gray cast irons at different impact angles, Wear, 261: p.p. 622-633, 2006.
27. I. Finnie, J. Wolak and Y. Kabil, Erosion of Metals by Solid Particles, Journal of Materials, 2: p.p. 682-700, 1967.
28. S. M. Shah, S. Bahadur and J. D. Verhoeven, Erosion Behavior of High Silicon Bainitic Structures, Ⅱ: High Silicon Steels, Wear, 113: p.p. 279-290, 1986.
29. E. E. Glickman and M. Nathan: Mater. Charact. 62: p.p. 925-9301, 2011.
30. J. E. Hatch, Aluminum: properties and physical metallurgy, vol. 1: p.p. 50, ASM International, 1984.
31. 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: p.p. 63-78, 1998.
32. L. F. Mondolfo: Aluminum alloys structure & properties, Chapter 4-3: p.p. 806-842, 1976.
33. 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: p.p. 118-125, 2009.
34. S. J. Hales and T. R. Mcnelley: Acta Matall. 36: p.p. 1229-1239, 1998.
35. S. K. Hovis, J. Talia, and R. O. Scattergood, Erosion mechanisms in aluminum and Al-Si alloys, Wear, 107: p.p. 175-181, 1986.
36. Y. W. Shin, G. A. Sargent, and H. Conrad, Effects of microstructure on the erosion of Al-Si alloys by solid particles, MTA, 18: p.p. 437-450, 1987.
37. 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: p.p. 79-92, 2007.
38. 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: p.p. 22-30, 1998.
39. 劉中偉，片狀石磨鑄鐵與鋁-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。
40. 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: p.p. 131-138, 1998.
41. 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: p.p. 1781-1789, 2000.
42. 林佳緯，新型應變誘發熔融激化製程下Al-Mg-Si合金之微觀組織演變、機械性質以及沖蝕磨耗特性研究，國立成功大學材料科學及工程學系，博士論文，2016。
43. 林啟航，4384 Al-Si-Cu-Ni-Mg鋁合金切削斷屑性之時效處理效應，國立成功大學材料科學及工程學系，碩士論文，2012。
44. 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。
45. 余立仁，固溶熱處理與退火處理對6082鋁合金微觀組織與拉伸性質(常溫至500°C)之影響，國立成功大學材料科學及工程學系，碩士論文，2015。