In this paper, the effects of assembly gap, welding speed and welding current on the structure and performance of butt joint + lap joint are studied by taking 2219 aluminum alloy plate with 5 mm +7 mm thickness as the object. The 5 mm +7 mm butt + overlap joints of 2219 is welded by TIG as different process parameters according to the welding characteristics of 2219 aluminum alloy, and the structure analysis and mechanical properties test of the joints are carried out. The results show that ,the butt and lap joints under the three parameters are all well formed, the back welding leakage is smooth and uniform, and there is no undercut, sharp transition and spatter defects on the surface of the weld, the joints welded by smaller gap and larger current have better performance, and tensile strength can reach 72% of the base material. Suitable welding speed and current can inhibit the precipitation of the second term, thereby making the structure at the fusion line more uniform and improving the mechanical properties of the joint. It has certain reference value for welding process of the 2219 aluminum.
2219 aluminum alloybutt + overlap jointswelding processassembly gapwelding current
CHEN S H， LI L Q， CHEN Y B， et al. Sidiffusion behavior during laser welding-brazing of Al alloy and Ti alloy with Al-12Si filler wire［J］. Transactions of NonferrousMetals Society of China， 2010， 20（1）： 64-70.
YAN D Y，WU H Q，CHANG Z L．Analysis on The Properties of 2219 Aluminum Alloy Joints With Single-Layer Welding and Single-Sided Double-Layer Welding Process［J］．Aerospace Materials & Technology，2013，43（6）： 79-84．