Nd在挤压态AZ31镁合金中的行为及作用

Behavior and effect of Nd in as-extruded AZ31 magnesium alloy

通过金相显微镜、SEM和XRD观察研究挤压态AZ31-xNd镁合金的微观组织和析出相,并测试合金的室温和高温力学性能。结果表明:Nd在合金中以Al2Nd和Mg12Nd化合物形式存在,且随着Nd量的增加,其数量增加;Nd使合金的晶粒细化、室温和高温性能提高。加入0.6%Nd的合金晶粒尺寸由未加Nd时的26μm降至约10μm,加入0.6%Nd合金的室温抗拉强度、屈服强度和伸长率分别为325MPa、247MPa和18.1%。含Nd合金的抗拉强度和屈服强度随温度升高而下降,而伸长率随温度的升高而增加。

The microstructures and precipitated phases of as-extruded AZ31 magnesium alloy were studied by OM,SEM and XRD.The mechanical properties of the alloys at room temperature and high temperature were also tested.The results show that the addition of Nd results in the formation of Al2Nd and Mg12Ng phases in the matrix and the grain refinement in AZ31 alloy,and the amounts of Al2Nd and Mg12Nd phases increase with the increase of Nd addition.The mechanical properties at room temperature and high temperature are improved significantly due to the precipitation of second phases and grain refinement.The average grain size of alloy changes from 26μm without Nd to 10μm when added 0.6%Nd. The tensile strength,yield strength and elongation of as-extruded AZ31 alloy with 0.6%Nd are 325 MPa,247 MPa and 18.1%at room temperature.The tensile strength and yield strength of alloy with Nd decrease,but the elongation increases with increasing temperature.