Effect of SiC and TiC content on microstructure and wear behavior of Ni-based composite coating manufactured by laser cladding on Ti–6Al–4V

Abstract

The low hardness and poor wear resistance of titanium alloys limit their widespread industrial use. In this study, a composite coating made of Ni60, SiC, and TiC powders using laser cladding technology was used to improve the wear resistance of Ti–6Al–4V (TC4), with the microstructural characteristics, phase style, microhardness, wear behavior, and corrosion resistance studied to clarify the effects of SiC and TiC contents. The experimental results show that the main phases in the composite coatings are TiC, Ti5Si3, and Ti2Ni, which change little with changes in the TiC and SiC content. The prepared composite coatings significantly improved the hardness and wear resistance of the TC4 substrate with the 20% SiC coating showing the lowest wear rate. The main wear mechanisms of the composite coatings were the complex modes of adhesive, abrasive, and oxidative wear, and that of the TC4 substrate was microcutting. The corrosion potential (Ecorr) of TC4 is lower than that of the prepared composite coatings, and the corrosion current (Icorr) of TC4 is also higher. The corrosion resistance of the composite coatings—with intracrystalline corrosion as the primary corrosion mechanism—was better than that of the TC4 substrate.