Er对ZA73镁合金显微组织与力学性能的影响

Effects of RE Erbium Addition on Microstructure and Mechanical Properties of ZA73 Magnesium Alloy

采用光学显微镜(OM)、扫描电镜(SEM)、能谱分析、力学性能测试等研究了稀土元素Er对金属型铸造ZA73镁合金显微组织和力学性能的影响。试验结果表明,加入少量Er后晶界半连续分布的共晶化合物[τ(Mg32(Al,Zn)49)]变为颗粒状,并且合金中有细小颗粒状Er-Al化合物生成。Er的加入提高了合金在200℃时的力学性能,随着Er含量增加,合金强度提高,伸长率在Er含量为0.4%时出现峰值,为29%。高温下拉伸,合金的抗拉强度并不随温度的增高而持续降低,而是在150℃时达到最大值,为180MPa。

Effects of RE erbium on microstructure and mechanical properties of permanent mold casting ZA73 alloy were investigated by OM(optical microscope),SEM(scanning electron microscope),EDS(energy dispersive spectrum)and tensile testing.The results indicate that semi-continuous distributed eutectic compound [τ(Mg32(Al,Zn)49)] is converted into discontinuous globular particle on boundary with minor erbium addition,meanwhile,fine Er-Al phase in the alloy can be identified.Tensile testing reveals that with increasing in erbium content,the tensile strength is improved and elongation reachs a peak value with 0.4% Er addition at 200℃.Elevated tensile strength is firstly increased and then decreased with increasing in temperature,in which the maximum value of tensile strength can be obtained at 150℃.