A STUDY ON MICROSTRUCTURE CHARACTERISTICS OF IN SITU FORMED TiC REINFORCED COMPOSITE COATINGS

In situ synthesized TiC reinforced composite coating was fabricated by laser cladding of Al-Ni-Cr-C powders on titanium alloys, which can greatly improve the surface performance of the substrate. In this study, the Al-Ni-Cr-C laser-cladded composite coatings have been researched by means of X-ray diffraction, scanning electron microscope (SEM) and electron probe micro-analyzer (EPMA). There was a metallurgical combination between the Al-Ni-Cr-C laser-cladded coating and the Ti-6Al-4V substrate, and the micro-hardness of the Al-Ni-Cr-C laser-cladded coating was in the range of ~1200–1450 HV0.2, which was ~3–4 times higher than that of Ti-6Al-4V substrate. Furthermore, the reinforcement of the Al-Ni-Cr-C laser-cladded coating were mainly contributed to the action of the TiC, Ti3Al, Cr7C3, Al8Cr5 phases and the solution strengthening.