摘要
本研究在MgYZn合金(Mg97Y2Zn1)內分別添加5 wt%及10 wt%的碳化矽(SiC)粉末使用兩階段鑄造方法製備鎂基複合材料，探討其顯微結構、機械性質及腐蝕行為。
研究結果顯示MgYZn合金在添加SiC粉末顆粒後之相組成為α-Mg、Mg12YZn (LPSO相)及SiC。在硬度測試方面添加SiC粉末顆粒之MgYZn合金硬度皆會比無添加時來的高，而在進行機械拉伸試驗時， MgYZn合金其降伏強度和抗拉強度分別為46 MPa及170 MPa，在各別添加5 wt%、10 wt% SiC之鎂基複合材料，兩者機械強度明顯提升，分別為97 MPa、223 MPa以及91 MPa、238 MPa。藉由估算SiC含量，發現兩種鎂基複合材料之實際SiC含量差異不大，皆在3.5 wt%，故推測已達到目前鑄造方法所能添加SiC含量上限。
腐蝕浸泡試驗上，添加SiC粉末顆粒之MgYZn合金，腐蝕現象明顯比未添加SiC粉末顆粒的MgYZn合金來的劇烈，其原因為SiC粉末異質顆粒與母相間的間隙腐蝕，使得鎂基複合材料的耐蝕能力明顯降低。

Abstract
In this study, Mg-based metal matrix composites (MMC) were prepared by two-step casting of Mg97Y2Zn1 alloy with 5 and 10wt% of SiC particles. Microstructure, mechanical properties, and corrosion behavior of the prepared samples were investigated.
The composites contain α-Mg, Mg12YZn (LPSO) and SiC phase. By adding SiC particles, the MgYZn alloy’s hardness was increased; for tension test, yield strength and ultimate strength of MgYZn alloy were 46 MPa and 170 MPa, respectively. By adding 5 wt% of SiC particles, yield strength and ultimate strength were 97 MPa and 223 MPa; as for adding 10 wt% of SiC particles, yielding strength and ultimate strength were 91 MPa and 238 MPa. Mechanical strength was also enhanced after adding SiC particles. By estimating the amount of SiC, the actual amount of SiC in the two MMC was not very different, which is around 3.5 wt%. It was speculated that the limit of SiC which could be added into the Mg alloy by two-step casting has been reached.
The results obtained from immersion tests showed that the corrosion of MgYZn alloy with 5 or 10 wt% of SiC were more severe than that of MgYZn alloy. Pitting corrosion between SiC particles and Mg matrix led to decline corrosion resistance. The corrosion rate of Mg-based metal matrix composites is higher than Mg97Y2Zn1 alloy.

參考文獻

[1] 邱垂弘、楊智超，"輕金屬特刊－鎂合金成型技術之發展趨勢"，工業材料雜誌174期90年6月
[2] 葉圳轍，"輕金屬特刊－鎂合金成型產業現況"，工業材料雜誌186期91年6月
[3] A.Luo, J. Renaud, I. Nakatsugawa, and J. Plourde, " Magnesium Castings for Automotive Applications," JOM, pp. 28-29, 1995.
[4] R. J. Cheng, F. S. Pan, M. B. Yang, A. T. Tang, " Effects of various Mg-Sr master alloys on microstructural refinement of ZK60," Transactions of Nonferrous Metals Society of China, vol. 18, pp. 50-54, 2008.
[5] S. L. Sin and D. Dubé, "Influence of process parameters on fluidity of investment-cast AZ91D magnesium alloy," Materials Science and Engineering: A, vol. 386, no. 1-2, pp. 34-42, 2004.
[6] H. K. Srivastva, P. k. Bhardwaj, R. P. Gond, V. Tiwari, and R. Saroj, "Magnesium Matrix Composite: Problems and Possibility ," International Journal of Research vol. 03, no. 05, pp. 401-405, 2015.
[7] Y. Kawamura, "Flame-resistant Magnesium Alloys with High Strength," Magnesium Research Center (MRC), Kumamoto University, Japan
[8] T. Itoi, T. Seimiya, Y. Kawamura, and M. Hirohashi, "Long period stacking structures observed in Mg97Zn1Y2 alloy," Scripta Materialia, vol. 51, no. 2, pp. 107-111, 2004.
[9] Y. Z. Du, X. G. Qiao, M. Y. Zheng, D. B. Wang, K. Wu, and I. S. Golovin, "Effect of microalloying with Ca on the microstructure and mechanical properties of Mg-6 mass%Zn alloys," Materials & Design, vol. 98, pp. 285-293, 2016.
[10] X. Zhao, L. L. Shi, and J. Xu, "Biodegradable Mg-Zn-Y alloys with long-period stacking ordered structure: optimization for mechanical properties," J Mech Behav Biomed Mater, vol. 18, pp. 181-90, Feb 2013.
[11] C. J. Bettles and M. A. Gibson, "Current Wrought Magnesium Alloys Strengths and Weaknesses," JOM, vol. 57, no. 5, pp. 46-49, 2005.
[12] J. Y. Wang, A. Saufan, P. H. Lin, H. Y. Bor, S. Lee, and Y. Kawamura, "Mechanical properties and strengthening behavior of Mg–Zn–MM alloy," Materials Chemistry and Physics, vol. 148, no. 1-2, pp. 28-31, 2014.
[13] Y. J. Chen, Q. D. Wang, J. B. Lin, M. P. Liu, J. Hjelen, and H. J. Roven, "Grain refinement of magnesium alloys processed by severe plastic deformation," Transactions of Nonferrous Metals Society of China, vol. 24, no. 12, pp. 3747-3754, 2014.
[14] A. Dziubińska, A. Gontarz, K. Horzelska, and P. Pieśko, "The Microstructure and Mechanical Properties of AZ31 Magnesium Alloy Aircraft Brackets Produced by a New Forging Technology," Procedia Manufacturing, vol. 2, pp. 337-341, 2015.
[15] B. L. Mordike and T. Ebert, "Magnesium Properties – applications – potential," Materials Science and Engineering: A, vol. 302, pp. 37-45, 2001.
[16] 邱仁志，「AZ80鎂合金管材與棒材之熱擠成形性探討」，碩士論文，國立台灣科技大學，台北, 2007
[17] ASM, “Magnesium Alloys”, Metals Handbook 9th Edition, Vol.6, pp.425~434, 1985
[18] S. Zhang, X. Zhang, C. Zhao, J. Li, Y.Song, C.Xie, H. Tao, Y. Zhang, Y. He, Y. Jiang, Y. Bian, "Research on an Mg-Zn alloy as a degradable biomaterial," Acta Biomater, vol. 6, no. 2, pp. 626-40, Feb 2010.
[19] H. Pan, Y. Ren, H. Fu, H. Zhao, L. Wang, X. Meng, G. Qin, "Recent developments in rare-earth free wrought magnesium alloys having high strength: A review," Journal of Alloys and Compounds, vol. 663, pp. 321-331, 2016.
[20] 張永耀, “金屬熔銲學” .徐氏基金會, 下冊, pp.134~170, 台北, 1976
[21] A. C. Hanzi, I. Gerber, M. Schinhammer, J. F. Loffler, and P. J. Uggowitzer, "On the in vitro and in vivo degradation performance and biological response of new biodegradable Mg-Y-Zn alloys," Acta Biomater, vol. 6, no. 5, pp. 1824-33, May 2010.
[22] A. Inoue, M. Matsushita, Y. Kawamura, K. Amiya, K.Hayashi, and J. Koike, "Novel Hexagonal Structure of Ultra-High Strength Magnesium-Based Alloys," Materials Transactions, vol. 43, pp. 580-584, 2002.
[23] Y. Kawamura, M. Yamasaki, "Formation and Mechanical Properties of Mg97Zn1RE2 Alloys with Long-Period Stacking Ordered Structure," Materials Transactions, vol. 48, pp. 2986-2992, 2007.
[24] Y. Yamamoto, Y. Sakamoto, Y. Masaki, and S. R. Nishitani, "First Principles Calculations of Solute Ordering in Mg ­ Zn ­ Y Alloys," Materials Transactions, vol. 54, pp. 656-660, 2013.
[25] Y. Tang, B. Li, H. Tang, Y. Xu, Y. Gao, L. Wang, J. Guan, "Effect of long period stacking ordered structure on mechanical and damping properties of as-cast Mg–Zn–Y–Zr alloy," Materials Science and Engineering: A, vol. 640, pp. 287-294, 2015.
[26] H. Z. Ye and X. Y. Liu, "Review of recent studies in magnesium matrix composites," Journal of Materials Science & Technology, vol. 39, pp. 6153-6171, 2004.
[27] K. Deng, C. Wang, X. Wang, K. Wu, and M. Zheng, "Microstructure and elevated tensile properties of submicron SiCp/AZ91 magnesium matrix composite," Materials & Design, vol. 38, pp. 110-114, 2012.
[28] M. Habibnejad-Korayem, R. Mahmudi, and W. J. Poole, "Enhanced properties of Mg-based nano-composites reinforced with Al2O3 nano-particles," Materials Science and Engineering: A, vol. 519, no. 1-2, pp. 198-203, 2009.
[29] 陸仁凱，「7XXX系含鈧鋁合金的顯微結構與機械性質之分析」，碩士論文，國立中央大學，桃園, 2006
[30] W. Zhou and Z. M. Xu, "Casting of SiC Reinforced Metal Matrix Composites," Journal ofMaterials Processing Teclmology, vol. 63, pp. 358-363, 1997.
[31] 香港生產力促進局 材料及製造科技部，"鎂合金表面處理技術"，表面處理通訊第33期，pp. 125-130
[32] J. Zhang, J. Xu, W. Cheng, C. Chen, and J. Kang, "Corrosion Behavior of Mg–Zn–Y Alloy with Long-period Stacking Ordered Structures, " Journal of Materials Science & Technology, vol. 28, no. 12, pp. 1157-1162, 2012.
[33] F. Witte, F. Feyerabend, P. Maier, J. Fischer, M. Stormer, C. Blawert, W. Dietzel, N. Hort, "Biodegradable magnesium-hydroxyapatite metal matrix composites," Biomaterials, vol. 28, no. 13, pp. 2163-74, Apr 2007.
[34] C. Zhang, T. Zhang, Y. Wang, F. Wei, Y. Shao, G. Meng, F. Wang, K. Wu, "Effect of SiC Particulates on the Corrosion Behavior of Extruded AZ91/SiCp Composites during the Early Stage of Exposure" Journal of The Electrochemical Society, vol. 162 pp. C754-C766, 2015.
[35] B. Chen, D. Lin, X. Zeng, and C. Lu, "Effect of Solid Solution Treatment on Microstructure and Mechanical Properties of Mg97Y2Zn1 Alloy," Journal of Materials Engineering and Performance, vol. 22, no. 2, pp. 523-527, 2012.
[36] 陳莘樺，「改善鎂合金及鎂基複合材料AZ61/SiCp鑄錠品質並探討製程對其機械性質的影響」，碩士論文，國立台灣科技大學，台北, 2014
[37] 許傳仁，"鎂合金熔解技術在壓鑄製程之應用"，金屬工業研究發展中心 鑄造組
[38] Z. Fan, S. Ji, G. Liu, and E. Zhang, "Development of the Reho-diecasting process for Mg- alloys and their components," The Minerals, Metals & Materials Society, 2004.
[39] Z. Zhang, X. Liu, Z. Wang, Q. Le, W. Hu, L. Bao, J. Cui, "Effects of phase composition and content on the microstructures and mechanical properties of high strength Mg–Y–Zn–Zr alloys," Materials & Design, vol. 88, pp. 915-923, 2015.
[40] Z. Li, X. Gu, S. Lou, and Y. Zheng, "The development of binary Mg-Ca alloys for use as biodegradable materials within bone," Biomaterials, vol. 29, no. 10, pp. 1329-44, Apr 2008.
[41] M. Esmaily, J. E. Svensson, S. Fajardo, N. Birbilis, G. S. Frankel, S. Virtanen, R. Arrabal, S. Thomas, L. G. Johansson, "Fundamentals and advances in magnesium alloy corrosion," Progress in Materials Science, vol. 89, pp. 92-193, 2017.