AZ31镁合金TIG焊接头深冷处理及其力学性能  

Mechanical properties of tungsten inert-gas welded joints of AZ31 magnesium alloy by cryogenic treatment

作　　者：赵菲[1] 吴志生[1] 弓晓园[1] 曾亮[1] 

机构地区：[1]太原科技大学材料科学与工程学院,030024

出　　处：《焊接》2013年第10期42-44,74,共3页Welding & Joining

基　　金：山西省自然基金项目(2009011028-2);山西省留学基金项目(2012-075);太原市明星专项基金项目(09121013);太原科技大学博士启动基金项目(20122045)

摘　　要：介绍了AZ31镁合金TIG焊接工艺试验,在深冷处理温度为-160℃、保温时间分别为4 h,8 h和12 h条件下,对AZ31镁合金TIG焊接头进行深冷处理。对深冷处理前后的AZ31镁合金焊接接头进行了硬度及力学性能测试,并用扫描电镜SEM对拉伸试件的断口形貌进行观察分析。试验结果表明,经-160℃保温时间8 h的深冷处理,镁合金TIG焊接头母材区的硬度由HV68提高到HV76,焊接接头屈服强度和断后伸长率分别提高了13.4%和3.39%,表明深冷处理改善了镁合金焊接接头的力学性能。AZ31 magnesium alloy was welded by alternating current tungsten inert-gas welding.The deep cryogenic treatment experiment of the welded joint was carried out.The temperature of cryogenic treatment is-160℃,and the holding times is 4 h,8 h and 12 h.The hardness,tensile strength and bending strength of welded joints were tested,before and after deep cryogenic treatment.The fracture appearance was analyzed by scanning electron microscopy.Experimental results show that the hardness of joints reaches HV76 from HV68,the bending strength and the prolongation rate are increased by 13.4%and 3.39%after cryogenic treatment at- 160 ℃ for 8 h.Deep cryogenic treatment can improve mechanical properties of welded joints of magnesium alloy.

关 键 词：镁合金 TIG焊接头 深冷处理 力学性能 

分 类 号：TG444[金属学及工艺—焊接]