Laser Surface Alloying of Aluminium AA1200

Aluminium AA1200 was laser alloyed with mixtures of Ni, Ti and SiC powders using a 4.4 kW Rofin Sinar Nd: YAG laser to improve its surface hardness. The reactions of Al with Ni resulted in the in situ formation of Al3Ni and Al3Ni2 intermetallic phases while Ti reacted with Al to form an Al3Ti. Some of the SiC particles dissociated and reacted with either Al or Ti to form Al4C3, Al4SiC4, TiC or Ti3SiC2 phases. Si reacted with Ti to form a Ti5Si3 phase. Surface hardness increased after laser alloying due to the formation of intermetallic phases and metal matrix composites.