铸态Mg-4Al-2Si合金的显微组织与高温力学性能  

Microstructure and Elevated Temperature Mechanical Properties of As-cast Mg-4Al-2Si Magnesium Alloy

作　　者：宋佩维[1] 

机构地区：[1]陕西理工学院材料科学与工程学院,陕西汉中723003

出　　处：《铸造技术》2011年第2期214-218,共5页Foundry Technology

基　　金：陕西省自然科学基础研究计划资助项目(NO.2010JM6009);陕西省教育厅自然科学专项科研计划资助项目(NO.2010JK470)

摘　　要：采用光学显微镜、扫描电子显微镜、XRD衍射和拉伸试验等方法,研究了Mg-4Al-2Si(S42)镁合金的铸态组织和高温力学性能。结果表明,铸态合金主要由α-Mg基体、β-Mg17Al12相和Mg2Si相组成。其中,离异共晶β-Mg17Al12相呈网状分布于晶界上,初生Mg2Si相呈多边形块状随机分布于基体组织中,共晶Mg2Si相呈粗大的汉字状沿晶界或穿晶分布;150℃高温短时拉伸,合金的抗拉强度为97 MPa,屈服强度为58 MPa,伸长率为18%;拉伸断裂形式为准解理脆性断裂。The Microstructure and elevated temperature mechanical properties of the as-cast Mg-4Al-2Si（AS42） Magnesium Alloy were investigated by optical microscope,scanning electron microscope,XRD analysis and tensile test.The results show that the as-cast AS42 alloy are composed of α-Mg matrix,β-Mg17Al12 and Mg2Si phase.The reticular divorced eutectic β-Mg17Al12 distribution along the grain boundaries,the massive primary Mg2Si phase distribution in the matrix random,and the coarse ＇Chinese script＇ eutectic Mg2Si phase distribution along the grain boundaries or transcrystalline.According to the results of the elevated temperature transient tensile properties of alloy at 150 ℃,it is found that the ultimate tensile strength,yield strength,and rate of elongation is 97 MPa,58 MPa and 18% respectively.The fracture forms of the as-cast alloy is quasi-cleavage brittle fracture.

关 键 词：Mg-4Al-2Si镁合金 显微组织 高温力学性能 

分 类 号：TG136.1[一般工业技术—材料科学与工程]