Microstructure and dry sliding wear properties of laser clad Mo ₂Ni₃Si/NiSi metal silicide composite coatings

Mo₂Ni₃Si/NiSi wear-resistant metal silicide matrix composite coatings were fabricated on a substrate of an austenitic stainless steel 1Cr18Ni9Ti by laser cladding using Ni-Mo-Si elemental powder blends. The laser clad Mo₂Ni₃Si/NiSi composite coatings have a fine microstructure consisting of Mo₂Ni₃Si primary dendrites and the interdendritic Mo₂Ni₃Si/NiSi eutectics. Wear resistance of the laser clad coatings is evaluated under dry sliding wear test conditions. Influences of wear testing parameters on the wear resistance of laser clad coatings were studied and the wear mechanisms were discussed based on observations of worn surface morphology and subsurface microstructure. Results showed that laser clad Mo₂Ni₃Si/NiSi metal silicide composite coatings have excellent dry sliding wear resistance and low friction coefficient. Increasing test load has little influence on the wear mass loss of laser clad Mo₂Ni₃Si/NiSi metal silicide composite coatings.