【摘要】 针对Al-Cu-Mg系共晶型高强度LY12硬铝合金,进行了TIG与A-TIG焊接接头组织特征和熔深变化规律的研究。结果表明,在相同焊接规范下,TIG与A-TIG焊接接头焊缝区金相组织均为树枝状晶,热影响区金相组织均为等轴晶,差别在于A-TIG焊接接头组织晶粒较粗大。高倍显微镜下的金相组织显示,A-TIG焊缝区和热影响区中强化相数量比TIG焊多,且比TIG焊粗大。另外由于活性剂的加入,电弧产生收缩,热量集中,使得A-TIG焊熔深比TIG焊大。更多还原

【Abstract】 This paper have researched the microstructure characteristics and weld penetration change law of welded joint of Al-Cu-Mg system eutectic type high strength LY12 duralumin alloy under TIG welding and A-TIG welding.Results showed that the weld zone microstructure of TIG welding and A-TIG welding was dendritic crystal and the heat-affected zone microstructure of TIG welding and A-TIG welding was equiaxed crystal under the same welding specification.The difference was that the microstructure of A-TIG welded joint was coarser.The microstructure under advanced microscope showed that the weld zone and heat-affected zone of A-TIG had more strengthening phase than TIG and the strengthening phase of A-TIG was coarser than that of TIG.The weld penetration of A-TIG was deeper than TIG which had been caused by the addition of surfactant which leaded to arc constriction and heat concentration.更多还原