Microstructure and wear properties of laser melted γ-Ni/Mo2Ni3Si metal silicide “in situ” composite

Wear resistant γ/Mo2Ni3Si metal silicide “in situ” composite consisting of Mo2Ni3Si primary phase and lamellar γ/Mo2Ni3Si eutectics was fabricated by the laser melting process. The γ/Mo2Ni3Si composite has an excellent wear resistance under metallic dry sliding wear test conditions mating with hardened 1.0% C–1.5% Cr bearing steel. The excellent tribological properties are attributed to the high hardness of Mo2Ni3Si and the toughening effect of the ductile γ solid solution. Wear of the γ/Mo2Ni3Si composite is governed by the micro-cracking and spalling of the dendritic Mo2Ni3Si primary phase and the preferential wear of the interdendritic γ/Mo2Ni3Si eutectics.