Microstructure and properties of aluminum alloy welded by electric current supported laser welding

The 2219 aluminum alloy with 3 mm thickness was carried out by electric current supported laser welding, and the influences of electric current on the macrostructure, microstructure, porosity defect and mechanical properties of the weld were investigated. The results indicate that by using electric current, the coarse columnar grains transform into fine equiaxed grains and the grains are distinctly refined in weld zone. The formation of feather grains in the centre of weld during laser welding is prevented and the pores in the weld sharply reduce during electric current supported laser welding. The results show that the electric current supported laser welding process becomes more stable resulting in fewer pores in weld. The welded joints rupture at weld zone and the joint tensile strength evidently increases compared to that of laser welding. By using electric current, the grains are refined by the electromagnetic stirring and Joule heating effects, which improves the weld tensile strength.