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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%。
The Si-reinforced Mg97ZnY2 alloy was prepared by the ordinary casting method. The effects of different Si contents on the microstructure and mechanical properties of the Mg97Zn1Y2 alloy were investigated. The microstructure of the Mg97Zn1Y2 alloy was observed by optical microscope (OM). The microstructure and phase structure of the Mg97ZnY2 alloy with addition of Si Composition, tested the alloy hardness and tensile mechanical properties at room temperature. The results show that the granular Mg_2Si phase and the metastable Mg_5Si_6 phase are formed in the Mg97Zn1Y2 alloy after a certain amount of Si is added, and are enriched in the front of the solid-liquid interface during solidification, hindering the free growth of the α-Mg dendrite and thus fine As the content of Si increases, the hardness of the alloy increases continuously. When the content is 1.8%, the hardness of the alloy reaches 95.5 HV, increased by 18.5%. The tensile strength and elongation of Mg97ZnY2 alloy with 0.2wt% Si The growth rate of Mg97ZnY2 alloy was higher than that of as-cast Mg97ZnY2 alloy. The tensile strength reached 220 MPa, the elongation was 10%, the tensile strength increased by 24% and the elongation increased by 37%.