A COMPARATIVE STUDY OF LASER, CMT, LASER-PULSE MIG HYBRID AND LASER-CMT HYBRID WELDED ALUMINIUM ALLOY

摘要

Using cold metal transfer (CMT) welding which was a special pulse metal inert gas (MIG) welding method, a new hybrid welding, laser-CMT hybrid welding, was introduced to join aluminum alloy thin plate. In order to evaluate laser-CMT hybrid welding, a comparison research on the microstructures and mechanical properties of aluminum alloy joints made by laser welding (LW), CMT welding, laser-CMT hybrid welding (LCHW) and laser-pulse-MIG hybrid welding (LPHW) was carried out. Because of lower heat input, the LW and LCHW joints had smaller grain sizes and narrower widths of welds than these of CMT and LPHW joints. The ultimate tensile strengths of LW, CMT, LCHW and LPHW joints reached up to 220 MPa, 200 MPa, 219 MPa, and 198 MPa, respectively. Meanwhile, the LW and LCHW joints brought less deformation in comparison with CMT and LMHW joint. These results showed LCHW had obvious advantages in joint quality, indicating it would be a suitable technique for joining aluminum alloys.