Si对铸造Mg97ZnY2合金组织及性能的影响  

Effects of Si on Microstructure and Mechanical Properties of Mg97ZnY2 Alloy

作　　者：万迪庆[1,2] 袁艳平[1] 

机构地区：[1]华东交通大学机电工程学院,江西南昌330013 [2]西北工业大学凝固技术国家重点实验室,陕西西安710072

出　　处：《铸造技术》2016年第2期201-204,共4页Foundry Technology

基　　金：国家自然科学基金资助项目(51361010)

摘　　要：采用普通铸造法制备了Si增强的Mg97ZnY2合金,研究了不同Si含量对Mg97Zn1Y2合金组织及力学性能的影响,利用光学显微镜(OM)观察金相组织,XRD分析了加入微量Si的Mg97ZnY2合金组织及相组成,测试了合金硬度和室温拉伸力学性能。结果表明:加入一定量Si后,Mg97Zn1Y2合金组织中形成颗粒状Mg_2Si相及亚稳定Mg_5Si_6相,在凝固过程中富集于固-液界面前沿,阻碍α-Mg树枝晶的自由长大,从而细化合金铸态组织;随着Si的含量增加,合金的硬度不断提高,当含量为1.8%时,合金的硬度达到95.5 HV,提高了18.5%;加入0.2wt%Si的Mg97ZnY2合金抗拉强度和伸长率均高于铸态Mg97ZnY2合金,抗拉强度达到220 MPa,伸长率为10%,其抗拉强度增加了24%,伸长率增加了37%。Mg97ZnY2 alloys enhanced by Si were prepared using common casting method. The effects of Si contents on microstructure and mechanical properties of Mg97ZnY2 alloy were investigated. The microstructures were observed by the optical microscope （OM） and the phase components of the Mg97ZnY2 alloy with or without Si were analyzed by X-Ray diffraction （XRD）. Meanwhile, the tensile properties and hardness at room temperature were tested. The results show that the metastable Mg^Si6 phase and the Mg2Si phase particles were emerged among the solid-liquid interface of the Mg97ZnY2 alloy during solidification process, this refining the casting alloy. The hardness of alloy was improved with the increasing of the content of element Si. The hardness of alloy is 95.5 HV when the content of element Si reaches 1.8%, which is increased by 18.5%. The tensile strength and elongation of Mg97ZnY2 alloy after adding 0.2wt%Si are higher than that of casting Mg97ZnY2 alloy, tensile strength reaches 220 MPa and the elongation is 10%. The tensile strength and elongation is increased by 24% and 37%, respectively.

关 键 词：镁合金 Si变质 力学性能 

分 类 号：TG146.22[一般工业技术—材料科学与工程]