Development and characterization of Ni60 alloy and SiC ceramic reinforced metal matrix composite coating on Ti-6Al-4V using laser cladding with coaxial powder feeding system

The main objective of this study was to develop a metal matrix composite (MMC) coating on Ti-6Al-4V substrate using a laser cladding method with coaxial powder feeding system. This study investigated the effectiveness of a novel material combination of Ni60 alloy and SiC ceramic in improving the surface properties of titanium alloys. The coatings were analyzed for their phase composition, microstructure, and elemental distribution. The microhardness, tribological properties, and wear mechanism of the coatings were evaluated using a Vickers microhardness tester and a ball-on-disk sliding test under dry conditions. The laser clad coatings consisted mainly of TiC, TiC+TiB eutectic, Cr₇C₃, Ni₃Ti, and γ-Ni. The MMC coatings demonstrated significantly improved microhardness values, wear resistance, and tribological properties compared to those of the titanium substrates, due to the in situ generation of hard particles and dispersion strengthening of the supersaturated solid solution. However, excessive SiC content resulted in increased friction coefficient, instability, and irregular wear characteristics due to brittle debonding on the wear surface. This study identified the optimal combination ratio of Ni60 and SiC powder for improving the performance of the MMC coating and proposed future research directions for further enhancing the coating properties.