Mg及Mg-Sn合金的显微组织和力学性能

Microstructure and Mechanical Properties of Mg and Mg-Sn alloy

采用光学显微镜、扫描电镜、EDX分析及XRD分析研究了铸态Mg-xSn(x=2,4)合金的显微组织和物相组成。采用万能试验机、布氏硬度计测试了合金的拉伸性能和硬度。结果表明,Sn的加入使纯镁铸态组织由粗大的等轴晶转变为树枝晶,晶粒得到明显细化,并且随Sn含量的增加细化效果越加明显。组织中同时形成了硬度高、热稳定性好的相Mg2Sn。随着Sn含量的增加,合金的硬度与抗拉强度均有明显提升。

The microstructure and phase constituent of as-cast Mg-xSn （x=2, 4） alloys were studied by optical microscopy, scanning electron microscopy, energy dispersive X-ray analysis, X-ray diffraction analysis. The tensile properties and hardness were tested by universal testing machine and brinell hardness tester. The results show that the adding Sn into magnesium modifies the microstructure of magnesium ingot. The microstructure of coarse equiaxed grains transforms into dendrites with grain refinement, and the grain refinement effect becomes obvious with the increase of Sn content. The Mg2Sn precipitates with high hardness and high thermal stability can be observed in the microstructure. The brinell hardness and tensile properties grows with the increase of Sn content.