Sn含量对二元Mg-Bi合金显微组织和力学性能的影响

Effect of Sn Content on Microstructure and Mechanical Properties of Binary Mg-Bi Magnesium Alloy

采用OM、SEM、XRD、EDS、维氏硬度计和电子拉伸试验机研究了Sn对Mg-3.3Bi合金显微组织和力学性能的影响.结果表明：加入Sn后,合金品粒尺寸随着Sn含量的增加先减小后增大,在添加4％Sn时最小;Sn元素能在显微组织中形成规则球状的Mg2Sn相,Mg2Sn相具有高硬度、高熔点以及热稳定性好的优点,对Mg-Y3Bi-Sn合金具有很好的强化效果;Sn元素在0～6％变化时,合金的抗拉强度、伸长率和硬度都呈现先升高后降低的趋势,当Sn含量为4％时合金的力学性能出现最佳配合.

The effects of Sn content on as-cast microstructure and mechanical properties of Mg-3.3Bi magnesium alloy were studied by using microscropy （OM）,scanning electron microscopy （SEM）,X-ray diffraction （XRD）,energy dispersive spectroscopy （EDS）,micro-hardness tester and electronic tensile testing machine in this study.The results indicate that with the addition of Sn,the grain size of this alloy increase firstly and then decrease with Sn content increasing,the size is the smallest with 4％Sn,The spherical Mg2Sn phase with high hardness,high melt point and good heat stability is found,which has good strength effect on Mg-3.3Bi-Sn alloy.When Sn element changes from 0 to 6％,tensile strength,elongation and hardness of the alloy display a trend which increase firstly and then decrease.The maximum tensile strength,elongation and hardness match better when Sn content is 4％.