Effect of TiC content on the microstructure and properties of large-area laser-cladded TiC Ni-based composite coatings

The study of effect of TiC content (10%, 20% and 30%) in Ni-matrix on the microstructure and properties of composite cladding prepared by laser cladding was reported in the present. Developed clads were characterized by SEM, EDS, XRD, microhardness tests, friction and wear tests and electrochemical tests. The experimental results show that the TiC/Ni composite coating had good quality and strong metallurgical bonding with the substrate. As the TiC content increases, distribution of TiC densified, the grain size increased, and the average hardness of the coating increased to 667.87 HV_0.2, which is approximately three times that of carbon steel. Moreover, as the TiC content increased, the friction coefficient of the coating decreased gradually. However, the friction coefficient of the 10% TiC coating was the most stable, as wear time increased. The electrochemical results showed that the corrosion resistance of the 10% TiC coating was the best. As TiC content increased, the corrosion resistance of the composite coating first decreased and then increased. (paper)