Effect of Ti2SnC mass fraction on microstructure and friction-wear performance of laser cladded Ni-WC coatings under WS2 lubrication condition

Ni-WC coatings with the different Ti2SnC mass fractions were prepared on the substrate of S136 steel by laser cladding (LC), in which the metallurgical bonding was formed at the coating interfaces. The microstructure and phases of obtained coatings were analyzed using a super depth of field microscope (SDFM) and X-ray diffraction (XRD), respectively. The effect of Ti2SnC mass fraction on the microstructure and tribological properties of Ni-WC coating were investigated using a ball-on-disc wear tester, and the wear model was also established to analyze the role of Ti2SnC phase in the friction process. The results show that the Ni-WC-8%Ti2SnC coating has the lowest coefficient of friction (COF) and wear rate among the three kinds of coating, and the wear mechanism is abrasive wear, which is contributed to the friction reduction and wear resistance roles of Ti2SnC phase. Furthermore, the COF and wear rate of Ni-WC coating can be reduced by the addition of appropriate Ti2SnC mass fraction, which may provide the reference for the friction and wear of Ti2SnC MAX phase in the coating field.