超声对AZ31合金激光焊接头组织与性能的影响  

Effects of Ultrasonic Treatment on Microstructure and Properties of AZ31 Magnesium Alloy Welded Joint by Laser Welding

作　　者：沈言锦[1,2] 刘海渔 李雪丰 陈学永 

机构地区：[1]湖南汽车工程职业学院 [2]湖南大学材料科学与工程学院 [3]江西昌河铃木汽车有限责任公司 [4]中建五局第三建设有限公司

出　　处：《特种铸造及有色合金》2016年第4期353-356,共4页Special Casting & Nonferrous Alloys

基　　金：国家自然科学基金资助项目(51274092);湖南省教育厅科学研究课题资助项目(15C0710)

摘　　要：采用激光焊接方法对AZ31镁合金薄板进行焊接,借助金相显微镜、布氏硬度计、拉伸试验机等手段研究超声波功率对焊接接头组织与性能的影响。同时利用图像分析软件Image-Pro Plus测量焊缝平均晶粒尺寸。结果表明,超声波功率对接头组织与性能影响明显。随着超声波功率的增加,空化效应以及声流作用越来越明显,平均晶粒尺寸由54μm减小到24μm,接头宏观硬度与抗拉强度均呈先增加后减小的变化。其中当超声波功率增加至1 200W时,平均晶粒尺寸最小,其最小值仅为24μm,而宏观硬度(HB)与抗拉强度均达到最大值,分别为56和286.54 MPa。AZ31magnesium alloy sheets were welded by laser welding.Effects of ultrasonic power on the microstructure and properties of the welded joint were investigated by optical microscopy,Brinell hardness tester and tensile testing machine.In addition,the average grain size of the welding joint was calculated by the Image-Pro Plus software.The results show that effects of ultrasonic power on microstructure and properties of the coating exhibit very obvious.With increasing in ultrasonic power,the average grain size is decreased from 54μm to 24μm as a result of obvious cavitation effect and acoustic stream.The macro-hardness and tensile strength of the welding joint are increased at first and then decreased.When the ultrasonic power is 1 200 W,the average grain size reaches 24μm.Meanwhile,the macrohardness and tensile strength of the joint reach 56 HB and 286.54 MPa,respectively.

关 键 词：镁合金 超声波功率 激光焊接 晶粒细化 

分 类 号：TG456.7[金属学及工艺—焊接]