Texture evolution in Nd:YAG-laser welds of AZ31 magnesium alloy hot rolled sheets and its influence on mechanical properties

AZ31 hot rolled magnesium alloy presents a strong basal texture. Using laser beam welding (LBW) as a joining process induces high temperature gradients leading to major texture changes.Electron back scattered diffraction (EBSD) was used to study the texture evolution, and tensile tests coupled with speckle interferometry were performed to understand its influence on mechanical properties. The random texture obtained in the LBW fusion zone is mainly responsible for the yield strength reduction.

Research highlights▶ AZ31 LBW fusion zone results in Mg17(Al–Zn)12 precipitation, twins formation and {0 0 2} texture modification. ▶ The mechanical properties were reduced after LBW but the fracture occurred in the base metal. ▶ The mechanical properties were reduced after LBW but the fracture occurred in the base metal. ▶ A recovery of elongation and UTS can be achieved by a 300 °C/1 h heat treatment. The texture evolution is mainly responsible for the yield strength reduction in the fusion zone.