Zn含量对铸态Mg-2Er合金的微观结构及力学性能影响

采用XRD和SEM等微观表征技术研究不同Zn添加量对Mg-2Er合金微观组织和力学性能的影响。结果表明：当Zn添加量为1%和2%时,合金主要相组成为W相和α-Mg;当Zn添加量为4%-10%时,合金中则有I相析出,合金相成分变为W相、I相和α-Mg;当Zn添加量增加至12%时,W相消失,合金中主要第二相则为I相和Mg4Zn7相。当Zn添加量为6%时,合金具有较好的拉伸力学性能,其抗拉强度、屈服强度和伸长率分别为224 MPa、134 MPa和10.4%。

Effect of Zn addition on microstructure and mechanical properties of as-cast Mg-2Er alloy

The effect of Zn addition on microstructure and mechanical properties of the Mg-2Er alloy was investigated by X-ray diffraction （XRD） and scanning electron microscope （SEM）. The results show that the alloys with 1%and 2%Zn （mass fraction） are composed of the W-phase and theα-Mg matrix. Meanwhile, the addition of 4%-10%Zn results in the formation of the I-phase, the W-phase and theα-Mg matrix. When the addition of Zn reaches 12%, the W-phase disappears and the phase constituents of the alloys mainly include the I-phase and the Mg4Zn7 phase besides theα-Mg solid solution. The alloy containing 6%Zn has better mechanical properties, of which the ultimate tensile strength （UTS） and the yield tensile strength （YTS） are about 224 MPa and 134 MPa, respectively, companying an elongation of 10.4%.