Bi变质原位自生Mg_2Si/Al复合材料的研究  

An Investigation of Bi Modification of in Situ Mg2Si/Al Composite

作　　者：司颐[1] 王喆[2] 武晓峰[2] 

机构地区：[1]辽宁石化职业技术学院应用化学系 [2]辽宁工业大学材料科学与工程学院

出　　处：《特种铸造及有色合金》2012年第9期846-849,共4页Special Casting & Nonferrous Alloys

基　　金：辽宁省教育厅重点实验室资助项目(20060394)

摘　　要：采用纯Bi对原位自生Mg2Si/Al复合材料进行变质;采用金相显微镜等观察了变质前后材料的微观组织;测试了材料的拉伸性能;并对变质前后合金的断口形貌进行了分析。结果表明,在原位自生Mg2Si/Al复合材料中添加适量的金属Bi对初生Mg2Si和共晶Mg2Si能够同时起到良好的变质作用,初生Mg2Si的形貌由粗大的树枝状或多角形块状转变为细小的块状,尺寸由70μm减小到6μm,而共晶Mg2Si则由粗大的片状转变为细小的片状、纤维状或点状。经1.0%的Bi变质后,材料的拉伸性能得到大幅度提高,抗拉强度从175MPa提高到260MPa,提高了48.6%,伸长率从3.5%提高到7.0%。In situ Mg2Si/Al composites were modified with pure Bi.The microstructures before and after modification were observed by OM（optical microscope）,and tensile properties of the composites modified were measured,and the fracture morphologies were analyzed by SEM（scanning electron microscope） before and after modification.The results show that the addition of proper amount of Bi has significant modification effect on both primary and eutectic Mg2Si in the composites.The morphology of primary Mg2Si is changed from dendritic to polyhedral shape,and the grain size is refined from 70 μm to 6 μm,meanwhile,the eutectic Mg2Si is transformed from flake-like to very short fibrous or dot-like.The tensile strength of the alloy modified by 1.0% Bi is increased from 175 MPa to 260 MPa,and its elongation is increased from 3.5% to 7.0%.

关 键 词：MG2SI AL复合材料 BI 变质 初生和共晶Mg2Si 力学性能 

分 类 号：TB331[一般工业技术—材料科学与工程]