铸态AZ91D镁合金双面TIG焊焊接接头组织研究  

Microstructure of Welded Joint of Die-cast AZ91D Alloy Plates Welded by TIG

作　　者：郭强[1] 游国强[1,2] 武婧亭[1] 

机构地区：[1]重庆大学材料科学与工程学院,重庆400030 [2]国家镁合金材料工程技术研究中心,重庆400030

出　　处：《热加工工艺》2011年第3期131-133,共3页Hot Working Technology

基　　金：重庆市科技攻关项目(CSTC2009AB4010);广东省科技攻关项目(2008A090300004)

摘　　要：对3mm厚铸态镁合金进行TIG焊研究,采用交流、双面焊接,其正面焊接电流为120A,背面焊接电流分别为80、90、100A,焊接速度和保护气体流量不变,焊接完成后按照标准程序对焊缝取样,用光学显微镜观察焊接接头的微观组织。分析表明:焊缝表面成形不好,焊缝表面存在明显缺陷;随着背面焊接电流的增加,焊缝中网状β-Mg17Al12相减少,而颗粒状的β-Mg17Al12相增多。As-cast AZ91D alloy plate with 3 mm thickness was welded by both sides using TIG.The welding process was that the current of first side was AC 120A and that of reverse side was 80A,90A and 100A,the welding speed and protection gas flow was constant.After welding,the cross-sections of the sample were prepared using standard procedures.The microstructure was investigated by optical microscopy.The results show that the surface appearance of the weld beads is not good,there are some visible defects;with the increase of electric current of reverse side,the amount of the continuous β-Mg17Al12 phase decrease,while the amount of the granular β-Mg17Al12 phase increase.

关 键 词：AZ91D镁合金 TIG焊 焊接接头 微观组织 

分 类 号：TG146.22[一般工业技术—材料科学与工程] TG444.74[金属学及工艺—金属材料]