Cu和Ce对Mg-1.5Zn-0.2Mn合金组织和力学性能的影响

Effects of Cu and Ce on microstructure and mechanical properties of Mg-1.5Zn-0.2Mn alloy

本文通过光学显微镜、拉伸试验机对比研究了Ce、Cu元素对Mg-1.5Zn-0.2Mn合金组织和力学性能的影响。研究结果表明,Cu、Ce元素对铸态Mg-1.5Zn-0.2Mn合金晶粒细化效果并不明显,但经350℃热变形后,能显著细化挤压态Mg-1.5Zn-0.2Mn合金的晶粒组织,其中Ce细化晶粒的效果更加明显,而且Ce能够抑制合金的动态再结晶。此外,Cu、Ce元素的添加均能提高Mg-1.5Zn-0.2Mn合金沿ED和TD方向的屈服强度和抗拉强度,其中Ce元素提高幅度更大,Mg-1.5Zn-0.2Mn-0.2Ce合金ED、TD方向屈服强度分别为185 MPa和162 MPa。与此同时,这两种元素还可以改善Mg-1.5Zn-0.2Mn合金板材强度的各向异性,其中Cu元素的改善效果更明显。

The effects of Ce and Cu on microstructure and mechanical properties of Mg-1. 5 Zn-0. 2 Mn alloy were investigated by means of optical microscope（ OM） and tensile testing machine. The results show that the addition of Ce and Cu play a negligible effect on the grain size of the as-cast Mg-1. 5 Zn-0. 2 Mn alloy,but could significantly refine the grain structure of the as-extruded alloy. Moreover,the Ce addition could suppress the recrystallization during hot deformation. The strength in ED and TD direction was enhanced by the addition of Ce or Cu and a better mechanical properties could be achieved in Ce-bearing alloy. After 350 ℃ extrusion,the Ce-containing alloy exhibits the best yield strength in ED（ 185 MPa） and TD（ 162 MPa） direction. In the meantime,the addition of Cu and Ce can improve the anisotropy of strength in Mg-1. 5 Zn-0. 2 Mn alloy,and the effect of improving sheet anisotropy by adding Cu is more obvious.