摘要
采用CMT焊对AZ31B镁合金和HDG60镀锌钢异种材料进行熔钎焊.在试验中,采取了搭接焊的方式,通过调整焊接参数得到最佳焊接成形.使用扫描电子显微镜(SEM)、能谱分析(EDAX)、电子探针、X射线衍射(XRD)及拉伸试验对焊接接头微观连接机制及性能进行研究.结果表明,镁和镀锌钢能够形成良好的搭接接头.焊接接头可以分成焊缝区、结合界面、熔合区.结合面主要有Al,Zn,Mg三种元素,主要相有Al12Mg17,Mg2Zn11,Al7Zn3及少量的MgFeAlO4复合氧化物.Zn和Al元素对镁钢连接起着关键作用,Zn在焊接接头形成过程中仍有一定的流动作用.在拉伸试验中,焊接接头试样几乎都断裂在熔合区,抗剪强度可达218 MPa.
Fusion-brazing of AZ31B magnesium alloy to HDG60 galvanized mild steel sheets was carried out by Cold Metal Transfer( CMT) technique. The optimized weld appearance was obtained by adjusting welding parameters. The bonding mechanism and mechanical properties of welding joints were studied by scanning electron microscope( SEM 6700F) equipped with energy dispersive X-ray spectrometer( EDS), electron probe microanalysis( EPMA),X-Ray analysis and universal tensile testing machine. Based on the experimental results,it was found that satisfied welded joints can be produced between magnesium and galvanized steel sheets. The welded joints were composed of weld metal,brazed interface and fusion zone. The brazed interface between the magnesium weld metal and galvanized steel primarily consisted of Al,Zn,Mg intermetallics and solid solution,such as Mg solid solutions,MgFeAlO4,Al7Zn3and Mg2Zn11. Zn and Al played key roles in bonding of Mg / steel joints,and Zn had flow effect on the formation of welded joints.During the tensile test of welded joints,the specimens fractured through the fusion zone,and the tensile-shear strength reached218 MPa.
出处
《焊接学报》
EI
CAS
CSCD
北大核心
2013年第9期21-24,114,共4页
Transactions of The China Welding Institution
基金
国家自然科学基金资助项目(51265028)
关键词
冷金属过渡焊
异种金属
熔钎焊
连接机制
cold metal transfer welding
dissimilar metals
fusion-brazing
bonding mechanism
