Mg-9Gd-3Y-0.6Zr-0.05Ag镁合金模锻件微观组织及力学性能不均匀性研究

基于DEFORM-3D数值分析软件,模拟了Mg-9Gd-3Y-0.6Zr-0.05Ag镁合金模锻件的成形过程,并研究了其顶部(T)、中部(M)和底部(B)的微观组织和力学性能。结果表明:模锻成形后,模锻件内部区域的温度和应变沿挤压方向从顶部至底部的分布不均匀,其中,温度呈现逐渐升高的趋势,应变呈现先增大、后减小的趋势。在晶粒尺寸与织构的共同作用下,模锻件底部的屈服强度最高、中部次之、顶部最低。模锻件温度和应变的分布特点导致了其中部具有更加均匀的组织和较弱的织构,从而体现出最优的综合力学性能,即:屈服强度为198 MPa、抗拉强度为312 MPa、伸长率为17.0%。

Study on inhomogeneity of microstructure and mechanical property for Mg-9Gd-3Y-0.6Zr-0.05Ag magnesium alloy die forgings

Based on the numerical simulation software DEFORM-3D,the die forging process of Mg-9Gd-3Y-0.6Zr-0.05Ag magnesium alloy was simulated,and the microstructures and mechanical properties in the top( T),middle( M) and bottom( B) of forgings were studied. The results show that after die forging,the temperature and strain in the inner region of forgings are unevenly distributed from T to B along the extrusion direction. Among them,the temperature gradually increases,and the strain first increases and then decreases. In addition,under the combined effect of grain size and texture,the yield strength of forgings is the highest in the B followed by the M,and it is lowest in the T. Thus,the temperature and strain distribution characteristics of forgings lead to more uniform structure and weaker texture in the M,which reflects the optimal comprehensive mechanical properties with the yield strength of 198 MPa,the tensile strength of 312 MPa and the elongation of 17. 0%.