Effect of TiC addition on the microstructure and properties of laser cladding Ni60A coatings on H13 steel surface

The paper uses a laser cladding process to prepare a composite coating of Ni60A and x% TiC (x = 0, 2, 4, 8) by mass percentage on the surface of H13 steel. The effects of different TiC additions on the microstructure and properties of the laser cladding coatings were analyzed by X-ray diffractometer (XRD), non-destructive testing, Penetrant testing (PT), optical microscope (OM), scanning electron microscope (SEM), energy dispersive spectrometer (EDS), micro-hardness tester, friction and wear tester, and electrochemical workstation. The results show that the coating microstructure without TiC addition was dominated by dendrites. The microstructure of the coatings appeared as short rods and equiaxed crystals after the addition of TiC. After analysis, hard reinforcing phases such as Cr23C6, Cr7C3, and TiCx were found to have a pinning effect at the grain boundaries, thus hindering the grain boundary slip. These can significantly increase the hardness of the coating. Most of the Ni60A coating with the addition of 2 wt% TiC (C2)coating curve is at the bottom end of the graph line. It has an average friction factor of 1.43 and a low wear weight loss. C2 coatings have less wear than C0 coatings.C2 coatings have 8.5% of the wear of C0 coatings.C2 has the best wear resistance. The hardness of the C2 coating is 662HV0.5, which is higher than other coatings with different TiC additions. The C2 coating had the lowest self corrosion current of 7.076 x10-7 A center dot cm-2. C2 coatings significantly appear grain refinement, lattice distortion, coating hardness, and wear resistance are high, with better corrosion resistance. The strengthening mechanism is mainly solid solution strengthening and fine grain strengthening together.