Evaluation of Microstructure and Mechanical Property of FSW Welded MB3 Magnesium Alloy

An experiment was carried out on the friction stir welding of MB3 magnesium alloy to determine welding parameters for obtaining an excellent weld appearance without void, cracking, or distortion. Frictional heat and plastic flow created fine and equiaxed grains in the weld nugget, and the elongated and recovered grains in the thermomechanically affected zone (TMAZ). The grains in the heat affected zone (HAZ) grow slightly. The mechanical property results show that maximum joint tensile strength can reach 97.2% of the parent material, which is stronger than that of fusion joints; and the failure almost occurs in the heat affected zone.