铸态Mg-Sn二元合金的显微组织与力学性能

Microstructure and Mechanical Properties of As-cast Mg-Sn Binary Alloys

通过光学显微金相定量分析、SEM扫描电镜及EDX分析、XRD分析以及抗拉强度、显微硬度测试等实验手段,研究添加量0～10%（wt）Sn的铸态Mg-Sn二元合金的显微组织与力学性能.实验结果表明,显微硬度随Sn的增加而增加,Mg2Sn的第二相强化是主要原因.Sn≤5%（wt）时,合金的抗拉强度和伸长率随Sn的增加而增加,Sn的细晶强化起到了主要作用.Mg-10%Sn的抗拉强度、特别是伸长率降低,细晶强化作用消失和脆性的Mg2Sn颗粒数量增多是主要原因.

The microstmcture and mechanical properties of as-cast Mg-Sn binary alloys were studied by optical mi- croscopy, scanning electron microscopy （SEM）, Energy Dispersive X-my （EDX） Analysis, X-my diffraction （XRD） quantitative and qualitative analysis, tensile strength and micro-hardness testing. The results showed that Mg - Sn binary alloy is composed of α- Mg matrix and Mg2Sn. The mechanical tests indicated that the micro-hardness of the alloy increases when Sn content raises, the main mason of which was the dispersion strengthening of Mg2Sn and the grain refinement strengthening of Sn. The tensile strength and elongation of the alloys grow with the increase of Sn content when the content of Sn ≤ 5 % （wt）. The grain refinement of Sn acts as the leading role in this content range of Sn. The tensile strength and especially elongation decline for Mg- %Sn alloy, which owes mainly to the disappearance of grain refinement strengthening and the increase of brittle Mg2Sn phase.