Microstructure and Residual Stresses in Dissimilar Mg-Al-Zn-alloy Single Overlap Laser Beam Welds

摘要

Microstructure, hardness and residual stresses of the laser beam overlap welds between AZ31B sheets and AZ31, AZ61 and AZ80 extruded profiles are investigated using microscopy and X-ray diffraction. The result of the investigations reveal that weld microstructure, the size of the HAZ, precipitate density and the maximum compressive residual stress values depend strongly on the Al content of the weld zone of two Mg-alloys.