2219 aluminum alloy is sensitive to the gas porosity. Variable polarity TIG arc welding technology can
independently adjust time and amplitude of positive and negative half period, therefore the VPTIG can be applied in
new launch vehicle. The tensile property of 2219 aluminum alloy VPTIG welding joint, tensile fractography analysis
and microstructure analysis are introduced in this paper. The results show that the strength factor of 2219 T62 aluminum
alloy VPTIG welding joint can reach 65%,the welding joint hybrid fracture and gas porosity of top layer more
than backing layer.