矽錳比對黃銅合金析出之影響

Effect of the Si/Mn ratio on the Precipitation of the Cu-Zn Alloys

洪章閔(Chang-Min Hung)

指導教授 ： 趙志燁

國立屏東科技大學/工學院/機械工程系所/碩士(2016年)

摘要

1.合金A(矽錳比0.23)、B(矽錳比0.25)鍛造後未經熱處理主要結構為：αCu+Mn5Si3相，合金C(矽錳比0.36) 鍛造後未經熱處理主要結構為αCu+βCu+Mn5Si3
2.合金A經高溫固溶後，其主要析出物為Mn5Si3，其析出物大小及數量隨著時間升高及持溫時間拉長而增加，當固溶溫度達790°C時基地產生βCu相；合金B經高溫固溶後主要析出物為Mn5Si3相與針狀析出物，固溶溫度達760°C時基地產生βCu相，當固溶溫度達820°C時其析出物消失；合金C固溶後主要析出物為Mn5Si3相固溶溫度在760°C以下時主要結構為αCu+βCu；760°C以上時為βCu單相結構。
3.時效處理後合金A、B主要析出物為Mn5Si3+針狀析出物；合金C主要析出物為Mn5Si3相，析出物數量與溫度、時間呈相關性。
4.在相同的熱處理條件下可發現矽錳的比例越高其Mn5Si3析出物數量及大小都有增加的趨勢；鐵元素對於Mn5Si3析出物的析出具有影響性。
5.針狀析出物經TEM擇區繞射圖分析後，為Orthorhombic結構其晶格常數a=0.486nm，b=0.443nm，c=1.095nm。

關鍵字

黃銅 ； 矽錳比 ； Mn5Si3 ； 針狀析出物

並列摘要

1.The microstructure of as-forged brass with lower (0.23 and 0.25) Si/Mn ratios is a αCu matrix with some Mn5Si3 precipitates. However, when heated at or above 820°C, the Mn5Si3 precipitates would be not found.
2.When aged above the temperature ranging between 760 and 790℃, some βCu-phase would be occurred on the brass with lower Si/Mn ratios(0.23, 0.25) resulting to being duplex phase matrix. However, the microstructure of the brass with higher Si/Mn ratiow(0.36) would be a single βCu phase.
3.During the high-temperature heated treatment, both of the size and amount of Mn5Si3 precipitates would be growth. In addition, when aged at lower temperature, some niddle-like precipitates are formed within the αCu matrix. Based on the kikuchi maps, these niddle-like precipitates could be analyzed to a Orthorhombic structure, of which the lattice parameters being a=0.486nm, b=0.443nm and c=1.095nm.
4.The amount of the Mn5Si3 precipitates and niddle-like precipitates formed within the αCu matrix could be consistent with the Si/Mn ratios. Addituionally, the contents of the Fe alloy element would play an important role on the precipitations during the aging processes.

並列關鍵字

Brass ； Si/Mn ratio ； Mn5Si3 ； niddle-like precipitate

參考文獻

[11] S. L. Semiatin, “ASM HANDBOOK Volume3 Alloy Phase Diagrams”, 2006, pp. 2. 182.

[14] Hamid Doostmohammadi, Hamid Moridshahi, Effects of Si on the microstructure, ordering transformation and properties of the Cu60Zn40 alloy., Journal of Alloys and Compounds, 2015, Vol. 640, pp. 401-407.

[19] Seungman Sohn, Tak Kang, The Effects of Tin and Nickel on the Corrosion Behavior of 60Cu-40Zn Alloy., Journal of Alloys and Compounds, 2002, Vol.335, pp. 281-289.

[20] Shufeng Li, Hisashi Imai, Katsuyoshi Kondoh, Akimichi Kojima, Yoshiharu Kosaka, Koji Yamamoto, Motoi Takahashi, Development of precipitation strengthened brass with Ti and Sn alloying elements additives by using water atomized powder via powder metallurgy route., Materials Chemistry and Physics 135, 2012, pp. 644-652.

[21] A.WAHEED, N. RIDLEY, Microstructure and wear of some high-tensile brasses, 1994, Journal of materials science, Volume 29, pp1692-1699.