Mg-Zn-Gd-Nd合金的微观组织与力学性能

Microstructure and Mechanical Properties of Mg-Zn-Gd-Nd Alloy

通过光学显微镜(OM)、扫描电镜(SEM)等方法,研究了Gd、Nd添加对铸态、挤压态Mg-3Zn合金的微观组织的影响,并测试了其室温拉伸力学性能。结果表明,Gd、Nd能显著细化Mg-3Zn合金的铸态组织,晶粒中含有大量的第二相。经挤压后组织得到细化,且含有大量的再结晶晶粒,第二相粒子沿挤压方向呈纤维状分布。随着Gd、Nd的加入,合金的抗拉强度和屈服强度显著提升,最大分别为265MPa、225MPa,伸长率降低。

The effects of Gd and Nd addition on the microstructure evolution of the as-cast and as-extruded Mg-3Zn alloy were investigated by optical microscopy(OM)and scanning electron microscopy(SEM).The tensile mechanical properties of the alloy at room temperature were tested.The results show that the as-cast microstructure of Mg-3Zn alloy can be refined significantly with addition of Gd and Nd,and a large number of second phases can be observed in the microstructure.The microstructure of the extruded alloy is refined with a large amount of recrystallized crystals,and the second phase particles are distributed in a fiber shape along the extrusion direction.With the addition of Gd and Nd,the tensile strength and yield strength of the Mg-3Zn alloy are improved significantly.The maximum value reach 265 MPa and 225 MPa,respectively,while the change of elongation can be decreased.