Laser-induced Ni(Ti) silicide formation

Abstract

Effects of Ti alloying during laser-induced Ni silicide formation is studied. Unique triple layer microstructures were found with the presence of supercell in the NiSi2 grains formed at the interface. This supercell formation was caused by a local ordering of Ni and Si atoms that favor lower free energy during rapid solidification. Ti rapidly segregates from the alloy melt and forms a protective TiOx overlayer on the surface during solidification. Melt front progressing towards the Ni-rich region leads to quenching of an amorphous layer sandwiched between NiSi2 grains and the TiOx overlayer.