Welding process and joint properties of hybrid welding on 2219 aluminum alloy

The correlation between three welding processes and joint microstructure as well as properties was investigated on 2219 aluminum alloy of 6 mm thickness. The three welding processes were TIG welding with filler wire, low-power laser assisted TIG hybrid welding and laser high-frequency pulse TIG hybrid welding respectively. The results showed that, compared with the TIG welding, the hybrid welding processe could improve the welding speed, reduce the heat input significantly, refine the microstructure of the joint, and reduce the width of eutectic α(Al) +θ(CuAl2), especially eliminate the porosities of fusion zone effectively. Furthermore both the joint properties and stress corrosion resistance were improved significantly. The average fracture time for 2219 aluminum alloy through the laser high-frequency pulse TIG hybrid welding was significantly longer than that through the TIG welding, which was about 93% of the average fracture time for 2219 base material.