Microstructure and dry sliding wear behavior of MoS2/TiC/Ni composite coatings prepared by laser cladding

A PRC-3 kW continuous wave CO2 laser was used to clad a MoS2/TiC/Ni coatings on the surface of a 1045 low carbon steel substrate. The microstructure and phase composition of the composite coating were studied. The typical microstructure of the composite coating is composed of multi-sulfide phases including binary element sulfides, ternary element sulfides, Ni, TiC and Mo2C. Wear tests were carried out using a FALEX-6 type pin-on-disc machine. The results showed that the MoS2/Ni coating (as a contrasted sample) exhibited the lowest friction coefficient and the largest weight loss in comparison to other investigated specimens. The friction coefficient of the MoS2/TiC/Ni coating is lower than that of quenched 45 steel and weight loss is only one-sixth of that of 45 steel. The worn surface of MoS2/TiC/Ni laser cladding coating is so clean and smooth (no noticeable groove and scratches visible) that the microstructure of coating is identified after dry wear test of 40 min.