往复挤压Mg-4Al-2Si合金的高温拉伸性能  

Elevated temperature tensile properties of Mg-4Al-2Si alloy prepared by reciprocating extrusion

作　　者：郭学锋[1] 杨文朋[2] 宋佩维[2] 

机构地区：[1]河南理工大学材料科学与工程学院,焦作454000 [2]西安理工大学材料科学与工程学院,西安710048

出　　处：《中国有色金属学报》2010年第6期1032-1038,共7页The Chinese Journal of Nonferrous Metals

基　　金：国家自然科学基金资助项目(50271054);教育部博士点基金资助项目(20070700003);河南省科技攻关资助项目(102102210031);河南省教育厅自然科学基金资助项目(2010A430008)

摘　　要：利用往复挤压制备细晶Mg-4Al-2Si合金,采用OM、XRD和SEM分析合金组织,在150℃和1.33×10-3s-1初始应变速率下测试合金的拉伸性能。结果表明:铸态组织由α-Mg、β-Mg17Al12、共晶型汉字状Mg2Si和少量初生块状Mg2Si组成。经过8道次往复挤压后,α-Mg和Mg2Si颗粒的尺寸分别为2.1和1.3μm,高温抗拉强度、屈服强度、伸长率和拉伸强度保持率分别为250MPa、197MPa、62%和88%。优良的高温性能归因于细小的基体组织和稳定的Mg2Si颗粒对晶界的有效钉扎作用。The fine grained Mg-4Al-2Si alloy was prepared by reciprocating extrusion（RE） .The microstructures were analyzed by X-ray diffractometry（XRD） ,optical microscopy（OM） and scanning electron microscopy（SEM） .The elevated temperature tensile properties were measured at 150℃with an initial strain rate of 1.33×10-3s-1.The results show that the as-cast alloy consists ofα-Mg,β-Mg17Al12 and Chinese script Mg2Si formed during the eutectic reaction and some primary block Mg2Si.After 8 passes reciprocating extrusion（RE） ,the average sizes ofα-Mg grain and Mg2Si particle are 2.1 and 1.3μm,respectively.The elevated temperature ultimate tensile strength,yield strength,elongation and retaining rate of ultimate tensile strength are 250 MPa,197 MPa,62%and 88%,respectively.The excellent elevated temperature properties are ascribed to the fine matrix and thermally stable Mg2Si particles,which can firmly pin the grain boundaries.

关 键 词：镁合金 MG-4AL-2SI合金 MG2SI 往复挤压 高温拉伸性能 

分 类 号：TG379[金属学及工艺—金属压力加工]