Mechanisms of Cracking in Laser Welding of Magnesium Alloy AZ91D

Considerable research has been carried out to study the laser welding of magnesium alloys. However, studies are mainly devoted butt welding, and there limited information in published literature concerning bead-on-plate AZ91D, even though is required for repair cast AZ91D parts with surface defects. In present investigation, cracking weld metal was observed when an alloy welded using method. This paper presents experimental results analyses show that “solidification cracking” initiated from under high thermal stresses. contrast “liquation heat affected zones tungsten inert gas same alloy. Laser power found be one main factors affecting distance crack propagation. The higher resulted longer propagation into metal. It demonstrated hot could avoided by lowering speed.