Laser Surface Alloying of Aluminium AA1200

Abstract

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.

Keywords:

• Laser alloying
• metal matrix composites
• intermetallic phases
• aluminium