Al对含有长周期有序堆垛结构Mg-Zn-Y-Mn合金组织和性能的影响

Infl uence of Al addition on the microstructure and mechanical properties of Mg-Y-Zn-Mn alloy containing LPSO phases

采用常规铸造方法制备了Mg_(94-x)Zn_(2.5)Y_(2.5)Mn_1Al_x(x=0,0.3,0.4,0.5)(a%)合金。利用光学显微镜、X射线衍射仪、扫描电子显微镜和电子万能试验机等对合金的铸态显微组织及力学性能进行了全面的分析。结果显示随着Al含量的增加,晶粒逐渐细化,在镁基体形成了一种新的Al(Y,Zn)_2相,而长周期相随着新相的增加逐渐减少,导致合金的力学性能得到显著提高。当添加0.4 a%的Al时合金的抗拉强度达到最大值260MPa,同时伸长率达到5.4%,与Mg_(94)Zn_(2.5)Y_(2.5)Mn_1相比分别提高了36%和12.5。随着Al含量进一步增加,长周期相消失,性能恶化。

The infl uence of Al additions(0,0.3,0.4,0.5)on the microstructure and mechanical properties of ascast Mg94Zn2.5Y2.5Mn1(a%)alloys were investigated.Results showed that with the addition of Al,a new Al(Y,Zn)2phase formed within the matrix while the LPSO phase was reduce as the new phases increase,which resulted in the dramatic change of the mechanical properties and get a peak tensile strength of260MPa with an elongation of5.4%when the Al addition was0.4%.