往复挤压Mg-Al-Si合金的高温拉伸性能  

Elevated temperature tensile properties of Mg-Al-Si alloys prepared by reciprocating extrusion

作　　者：郭学锋[1] 杨文朋[1,2] 宋佩维[2] 

机构地区：[1]河南理工大学材料科学与工程学院,河南焦作454010 [2]西安理工大学材料科学与工程学院,陕西西安710048

出　　处：《材料热处理学报》2012年第2期7-11,共5页Transactions of Materials and Heat Treatment

基　　金：国家自然科学基金(50271054);教育部博士点基金(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(RE-n,n为挤压道次)制备Mg-4Al-2Si(AS42)、Mg-4Al-4Si(AS44)和Mg-6Al-6Si(AS66)合金,并在150℃和1.33×10-3s-1的初始应变速率下测试合金的拉伸性能。结果表明:RE-8-AS42合金晶粒尺寸为2.1μm,Mg2Si颗粒尺寸为1.3μm;RE-4-AS42合金晶粒尺寸为4.8μm,组织中含有2～20μm的大块Mg2Si颗粒;RE-AS44和RE-AS66合金晶粒尺寸约为11μm,组织中存在>20μm的Mg2Si颗粒。合金拉伸强度随挤压道次增加而提高,RE-8-AS42合金性能最佳,抗拉强度、屈服强度和伸长率分别为250 MPa、197 MPa和62%,高的性能归因于细小的晶粒和阻碍晶界滑移的细小稳定Mg2Si颗粒。Mg-4Al-2Si（AS42）,Mg-4Al-4Si（AS44） and Mg-6Al-6Si（AS66） alloys were prepared by reciprocating extrusion（RE-n,where n is pass number）,and tensile properties of the alloys were examined at 150 ℃ with an initial strain rate of 1.33 × 10-3 s-1.The results show that the grain size of RE-8-AS42 alloy with Mg2Si particles of 1.3 μm is 2.1 μm,the grain size of 4.8 μm is observed in RE-4-AS42 alloy containing Mg2Si particles of 2-20 μm,and the grain sizes of RE-AS44 and RE-AS66 alloys are about 11 μm containing Mg2Si particles larger than 20 μm.The tensile strength increases with increasing extrusion passes.The RE-8-AS42 alloy has the best tensile properties with an ultimate tensile strength,a yield strength and an elongation of 250 MPa,197 MPa and 62%,respectively.The excellent properties are attributed to the fine grains and thermally stable fine Mg2Si particles,which can suppress grain boundaries sliding effectively.

关 键 词：Mg-Al-Si合金 往复挤压 高温拉伸性能 

分 类 号：TG146.2[一般工业技术—材料科学与工程]