摘要
For enhancement of mechanical properties in Mg-9Li-3Al alloys,Mg-9Li-3Al duplex alloys were alloyed by addition of Sn and Y.Microstructure evolution and mechanical property response of as-cast Mg-9Li-3Al alloys by alloying with Sn and Y were investigated by optical microscopy,scanning electron microscopy,X-ray diffractometry and tensile tests.The results indicate that considerable blocky dendrites of primaryαphase in Mg-9Li-3Al alloys become lath-like due to the addition of Sn.With addition of Y,Mg-9Li-3Al alloy consists of both block-like and lath-likeα-Mg dendrites.The as-cast Mg-9Li-3Al-1Sn-1Y alloy shows a yield strength of118MPa,ultimate tensile strength of148MPa and the elongation to failure of21%.Improvement in both strength and elongation of Mg-9Li-3Al alloys with Sn and Y addition is attributed to the combined action of MgLi2Sn and Al2Y intermetallic compounds.
为提高Mg-9Li-3Al双相镁合金的力学性能,向其中添加Sn和Y元素。通过金相显微镜观察、扫描电镜分析、X射线测试及拉伸试验分析研究Sn和Y元素对Mg-9Li-3Al合金显微组织演变和力学性能的影响。研究结果表明,Sn元素添加改变了块状初生α-Mg的形貌,使其呈板条状;Y元素添加使合金中α-Mg相呈现块状和板条状两种形态。铸态Mg-9Li-3Al-1Sn-1Y合金的屈服强度约为118 MPa,抗拉强度为148 MPa,断裂伸长率约为21%。在MLi_2Sn和Al_2Y金属间化合物的共同作用下,添加Sn和Y元素的Mg-9Li-3Al合金的强度和伸长率获得提升。
基金
Project(51401115) supported by the National Natural Science Foundation of China
Project(GN2013001) supported by the Independent Innovation Foundation of Shandong University,China
