Y对Mg-5Si合金微观组织和力学性能的影响  

Effect of Y on Microstructure and Mechanical Properties of Mg-5Si Alloy

作　　者：范晋平[1] 王浩[1] 武改林 蒋一锋 王晧 李尚明[1] FAN Jinping;WANG Hao;WU Gailin;JIANG Yifeng;WANG Hao;LI Shangming(College of Materials Science and Engineering, Taiyuan University of Technology, Taiyuan 030024, China)

机构地区：[1]太原理工大学材料科学与工程学院

出　　处：《太原理工大学学报》2020年第2期248-252,共5页Journal of Taiyuan University of Technology

基　　金：太原理工大学技术开发项目(RH19200007);太原理工大学本科教学改革项目(YB009)

摘　　要：针对耐热镁合金的应用需求,以Mg-5Si基础合金为研究对象,采用金属型铸造方法制备Mg-5Si-Y合金。利用扫描电子显微镜(SEM)、能量色散光谱仪(EDS)、光学显微镜(OM)和ICP光谱仪对合金组织及成分进行分析,利用拉伸试验机和布洛维硬度计对合金的屈服强度、抗拉强度、伸长率及硬度进行测试,探讨了Y含量对Mg-5Si合金微观组织和力学性能的影响。结果表明:不同Y含量下,初生Mg2Si相由树枝状变为多边形状,共晶Mg2Si相由汉字状变为层片状。Y质量分数为0.4%或0.8%时,α-Mg枝晶得到细化。Y质量分数为0.8%时,力学性能最佳。抗拉强度为107 MPa,屈服强度为91 MPa,伸长率为5%,硬度为138HV30.同时,在Y质量分数为1.2%的合金中发现了白色块状的Mg-Y-Si化合物。In order to meet the needs of heat-resistant magnesium alloy applications,Mg-5Si base alloys were used as a research object and Mg-5Si-Y alloys were prepared by permanent mold casting method.The microstructure and composition of the alloys were analyzed by scanning electron microscopy,energy dispersive spectroscopy,optical microscopy and ICP spectrometry.The yield strength,tensile strength,elongation and hardness of the alloys were tested on cupping machine and Vickers hardness tester.The effect of Y content on the microstructure and mechanical properties of Mg-5Si alloy was discussed.The results show that the morphology of primary Mg2Si phase changed from dendritic shape to polygonal shape,and that of eutectic Mg2Si phase changed from Chinese script shape to lamellar shape with the addition of various amount of Y.When the mass fraction of Y was 0.4%or 0.8%,α-Mg dendrites were refined.When the mass fraction of Y was 0.8%,the mechanical properties were the best.The tensile strength was 107 MPa,the yield strength was 91 MPa,the elongation was 5%,and the hardness was 138HV30.Meanwhile,some white bulk Mg-Y-Si compounds were found in alloys with the Y mass fraction 1.2%.

关 键 词：Mg-Si-Y合金 MG2SI 变质 微观组织 力学性能 

分 类 号：TG146[一般工业技术—材料科学与工程]