铸态Mg-xSn-2La合金的组织与性能  

Microstructure and Properties of As-cast Mg-xSn-2La Alloy

作　　者：章晓萍[1] 陈云贵[1] 肖素芬[1] 唐永柏[1] 牛高[1] 魏尚海[1] 赵源华[1] 

机构地区：[1]四川大学材料科学与工程学院

出　　处：《特种铸造及有色合金》2009年第3期266-269,共4页Special Casting & Nonferrous Alloys

基　　金：四川省科技厅重点攻关项目(04GG1589)

摘　　要：采用光学金相显微镜、SEM、EDS、XRD分析以及拉伸试验等试验手段,研究了Mg-xSn-2La(x=2.34、4.68、7.02、9.36)合金铸态下的组织和性能。结果表明,当Sn含量为2.34%时,合金主要由α-Mg和Mg-La-Sn稀土相组成;随着Sn含量增加,Mg2Sn数量增多,Mg-La-Sn稀土相逐渐粗化,细小的颗粒状稀土相减少,棒状稀土相增加,并且逐渐由晶界向枝晶间界分布,合金的抗拉强度与伸长率明显提高。Mg-7.02Sn-2La合金具有最高的抗拉强度(151MPa),而Mg-4.68Sn-2La具有最高的伸长率(12.7%),但是过多的Sn反而会导致合金力学性能下降。Microstructure and properties of Mg-xSn-2La(x=2.34～9.36)alloy were investigated by OM(optical microscope),SEM(scanning electron microscope),XRD(X-ray diffraction)and EDS(energy dispersive spectrum).It is found that with 2.34% Sn content,the alloy is mainly composed of α-Mg phase and Mg-La-Sn phase.With increasing in Sn content,Mg2Sn phase in the alloy is increased greatly and Mg-La-Sn phase is gradually coarsened,meanwhile,fine granular phase is decreased as rod-like phase increases.Furthermore,more RE phase tends to distribute along the interdentritic boundaries not to along grain boundary.In addition,tensile strength and elongation of the alloy are improved greatly with Sn addition.Mg-7.02Sn-2La alloy exhibits the optimum tensile strength of 151MPa while the Mg-4.68Sn-2La alloy shows the desirable elongation of 12.7%.However,excessive Sn addition can be detrimental to the mechanical properties of the magnesium alloy.

关 键 词：Mg—Sn-La合金 组织 性能 

分 类 号：TG136.1[一般工业技术—材料科学与工程]