2008 Volume 49 Issue 4 Pages 774-781
Laser welding is a promising joining method for magnesium alloys. The process reliability of 2-mm ZE41A-T5 butt joints welded by a 4 kW Nd:YAG laser was investigated from weld geometries, defects and mechanical properties using Weibull statistical distribution. Smooth, geometrically regular and macroscopically defect-free sound joints were obtained. However, sag, undercut, surface misalignment, and some variations in weld width and fusion zone area were also observed. The results indicated that tensile strength and elongation at fracture can be more accurately described by Weibull distribution. The modulus values of 31.98 and 22.52 were obtained for tensile strength in the as-welded and the aged conditions, respectively, indicating that tensile strength becomes more scattered after artificial aging. The aging treatment does not significantly affect mechanical properties, although it can provide stress relief. After laser welding, there is some degradation in tensile properties, especially elongation at fracture.