Remote Laser Welding of Multi-Alloy Aluminum at Close-Edge Position

6000 series (magnesium and silicon based) aluminum alloys are highly susceptible to hot cracking during laser beam welding. The occurrence of hot cracks depends on thermo-mechanical strain at the solidifying stage of the melt and in the micro-scale on the solidification structure. A new metallurgical approach to avoid these cracks by affecting the solidification process is using a multi-alloy aluminum with a silicon-rich layer. Within this paper infrared videos were used to investigate and compare the behavior of this new material with the 6xxx monolithic alloy at hot crack sensitive close-edge positions.