固溶处理对Mg-2Zn-3Y合金组织和性能的影响

Effect of solid solution treatment on microstructures and properties of Mg-2Zn-3Y alloy

为了研究固溶处理对铸态Mg-2Zn-3Y合金组织和性能的影响,采用光学显微镜、X射线衍射仪、扫描电子显微镜、拉伸试验机和维氏硬度计对固溶处理后的合金进行了组织分析及性能测试.结果表明:Mg-2Zn-3Y合金中含有LPSO相和W相,随着固溶温度的升高,块状LPSO相区域逐渐出现层片状形貌,W相发生球化、粗化和重熔现象,合金的抗拉强度、屈服强度、伸长率和硬度均呈现先升高后降低趋势;经450℃固溶12 h后,合金的强化效果最佳,抗拉强度为187 MPa,屈服强度为107 MPa,伸长率为8.0%,硬度为82.5 HV.

In order to study the influence of solid solution treatment on the microstructures and mechanical properties of as-cast Mg-2Zn-3Y alloy,the optical microscope(OM),X ray diffractometer(XRD),scanning electron microscope(SEM),tensile testing machine and Vickers hardness tester were used for the microstructure observation and mechanical properties testing of the alloy after solid solution.The results show that the Mg-2Zn-3Y alloy contains long period stacking ordered(LPSO)phase and W phase.With the increase of solid solution temperature,the area of bulky LPSO phase gradually appears lath-shaped morphologies,and the W phase gets spheroidized,coarsened and remelted.The ultimate tensile strength,yield strength,elongation and hardness of alloy increase first and then decrease with the increase of solid solution temperature.After the solid solution treatment at 450℃for 12 h,the alloy presents the best strengthening effect,and the ultimate tensile strength,yield strength,elongation and hardness are 187 MPa,107 MPa,8.0%,82.5 HV,respectively.