TIG重熔对6005A-T6铝合金焊接接头组织及性能的影响

Effect of TIG Remelting on Microstructure and Properties of 6005A-T6 Aluminum Alloy Welded Joint

针对铝合金焊接接头缺陷TIG重熔修复,采用6005A-T6铝合金作为母材,先采用MIG焊对母材进行焊接,焊后采用无脉冲TIG焊对焊趾处进行重熔,有无脉冲TIG焊对焊缝处进行重熔,对重熔前后的焊接试验件进行金相显微组织形貌及性能对比分析。结果表明,重熔后热影响区宽度明显大于重熔前,组织晶粒更加粗大,弥散相分布更加均匀;硬度最低值均出现在热影响区处,TIG重熔前后硬度值相差不大;抗拉强度较重熔前有所降低;TIG重熔前后断裂均为韧性断裂,说明重熔并没有改变6005A铝合金的断裂性质。因此可以采用TIG重熔技术对焊缝咬边等缺陷进行修补。

In order to repair the defect of the welded joint of aluminum alloy with TIG remelting,this paper discusses the use of 6005A-T6 aluminum alloy as the base material,first use MIG welding to weld the base material,then use pulsless TIG welding to remelt the weld toe,remelting the weld seam,and make a comparison analysis of the metallographic microstructure and properties of the welding test pieces before and after remelting.The results show that the width of heat-affected zone after remelting is obviously larger than that before remelting,and the grain size is coarser and the distribution of dispersion phase is more uniform.The lowest hardness values all appeared in the heat-affected zone,and there is little difference between the hardness values before and after TIG remelting.The tensile strength is lower than that before remelting.The fractures before and after TIG remelting are all ductile fractures,indicating that the fracture properties of 6005A aluminum alloy have not been changed by remelting.Therefore,TIG remelting technology can be used to repair defects such as weld undercut.