對(duì)2A12鋁合金進(jìn)行交流鎢極氬弧焊接,探討了ER4043焊絲和BJ-380A焊絲對(duì)焊接接頭組織、抗拉強(qiáng)度和硬度的影響.結(jié)果表明:兩種焊絲接頭焊縫區(qū)均為典型的鑄態(tài)枝晶組織,晶粒生長(zhǎng)方向以彎曲形狀垂直于焊接方向;與ER4043焊絲相比,BJ-380A焊絲接頭的熱影響區(qū)晶界中有更多的強(qiáng)化相析出;兩種焊絲接頭的抗拉強(qiáng)度均可達(dá)到母材的50%以上,拉伸斷裂部位均位于熱影響區(qū);與BJ-380A焊絲相比,ER4043焊絲接頭的強(qiáng)度和硬度更高,抗拉強(qiáng)度達(dá)到了母材的67.9%.
AC-TIG welding was performed on 2A12 aluminum alloy,the effects of ER4043 and BJ-380A welding wires on microstructure,tensile strength and hardness of welded joints were discussed.The results show that the typical cast dendrite was obtained in the weld seam zone of the joints with the two types of welding wires,and the grain growth direction was perpendicular to the welding direction.Compared with ER4043 welding wire,more strengthening phases precipitated at grains boundaries at heat affected zone of the joint with BJ-380A welding wire.The tensile strength of the both welded joints are over 50% of the base metal,and the fracture positions all were located on heat affected zone.Compared with BJ-380A welding wire,the strength and hardness of the joint with ER4043 welding wire were higher,and its tensile strength up to 67.9% of the base metal.