Investigation on high speed laser-MIG hybrid welding process of 6N01S-T5 aluminum alloy

To reduce the welding distortion and joint softening defects of 6N01S-T5 aluminum alloy, high-speed (4.8 m/min) laser-MIG hybrid welding process is performed. The mechanical properties and microstructure of welded joints are analyzed by microhardness test, tensile test, metallographic and SEM with EDS. The welding distortion of the butt joint is tested by coordinate measuring apparatus. The residual stress is measured by X-ray residual stress measurement instrument. The results show that the good appearance of weld is attained at the welding speed of 4.8 m/min. The average tensile strength of the high speed welding joint is 207 MPa, which is 71% of the base metal. Compared with the low speed welding process, the welding wire consumption is reduced by 68% and the welding efficiency is greatly improved at high speed welding process. Meanwhile, the width of the joint softening zone is reduced by 60%. The welding distortion is smaller and the range of residual tensile stress is narrower.