Mg-(6～8)A1-0.7Si合金的组织和力学性能分析

As-cast Microstructure and the Mechanical Properties About Mg-(6～8)Al-1Zn-0.7Si Alloys

通过金相观察、扫描电镜、X衍射分析和拉伸实验等方法，研究了Mg-（6～8）Al-0．7Si合金的铸态组织和力学性能．研究结果表明：添加了少量Sb和RE的Mg-（6～8）Al-0．7%Si的铸态组织主要由α—Mg基体、Mg17Al12相、Mg2Si相、Mg3Sb2相和少量针状Al4Si2Mn2Y相组成，并且随着Al含量的增加，试验合金组织中的Mg17Al12相增多，共晶析出物变得更加连续．同时，力学性能的测试结果表明：Al含量变化对于试验合金抗拉强度、屈服强度和延伸率的影响呈现出不同的变化规律．

In the paper the as-cast microstructure and the mechanical properties about Mg-（6～8）Al-0.7Si alloys were studied by metallurgical phase analysis, SEM analysis, XRD analysis and tensile test. The experimental results showed that the as-cast microstructure of Mg-（6～8）Al-0.7%Si alloys containing small amount Sb and RE are mainly composed of α -Mg matrix, Mg17Al12 phase, Mg2Si phase, Mg3Sb2 phase and a few needle shaped Al4Si2Mn2Y quaternion phase, and With the Al content increasing, the amount of MglTAl12 phase increased, th eutectic structure is more continuously. According to the experimental results of mechanical properities, It is found that the influenceing law of Al content on the UTS, YS and elongation is different.