Mg-6Zn-5Al-0.5Mn-1RE合金的显微组织和性能

Microstructure and properties of Mg-6Zn-5Al-0.5Mn-1RE alloy

试制备了Mg-6Zn-5Al-0.5Mn-1RE合金,对该合金的组织和性能进行了研究。试验结果表明,合金的铸态组织由基体α-Mg固溶体、分布在晶界上的三元相β(Mg17(Al,Zn)12)相、杆状的Mg-Al-Zn-RE四元相和一些呈球状的Al2MnRE相组成。这些第二相具有较好的热稳定性,经固溶处理后,只有部分β(Mg17(Al,Zn)12)相固溶到基体中,Mg-Al-Zn-RE四元相和Al2MnRE相变化不大。力学性能测试结果显示该合金室温性能优于ZA84。

Microstructure and properties have been studied for the prepared Mg-6Zn-5Al- 0.5Mn-IRE alloy. The results show that the as-cast alloy consists of matrix-ot（Mg） solid so- lution, β （ Mg17 （ Al, Zn） 12 ） ternary-phases, bacillary Mg-Al-Zn-RE quarternary phases and small globular A12MnRE phases in matrix. The β（ Mg17 （ Al, Zn） 12 ） ternary-phases are dis- tributed at grain boundaries. After solution treatment, part of β （ Mg17 （ Al, Zn） 12 ） ternary- phases dissolve into the matrix,most Mg-Al-Zn-RE quarternary phases and Al2MnRE phases stay unchanged. Thus, thermal stability of the second phases has been improved. The results of tensile and microhardness tests show that room-temperature properties of Mg-6Zn-5Al-0.5 Mn-1 RE alloy are better than those of ZA84 alloy.