Study on the friction and wear properties of nickel-based-WC-10Ni composite coatings prepared on the surface of TC4 titanium alloy

Abstract

A nickel-based-WC-10Ni composite coating was fabricated via vacuum brazing at 1160°C, using TC4 titanium alloy as the matrix, WC-10Ni powder as the hard phase, and BNi-5 as the brazing material. The study examined the coating’s microstructure and analyzed the impact of the WC-10Ni ratio and friction test temperature on its wear resistance, alongside a discussion of the wear mechanism. The results revealed that the hard layer of the composite coating comprised TiC, W, and minor amounts of Ti5Si3 and α-Ti, while the interface layer displayed a network structure of Ti2Ni and Ti5Si3. Using a Si3N4 ceramic ball as the counter-wear material, under conditions of a 10N load, 318r/min rotational speed, 3mm wear radius, and 30-minute wear duration, the average friction coefficients of the three composite coatings were 0.289, 0.241, and 0.271, and their wear rates were 65.8%, 39.7%, and 52.7% of the substrate, respectively. The 50% WC-10Ni coating exhibited the best wear resistance, with adhesive wear being the dominant mechanism, accompanied by minor abrasive wear. Friction tests on the 50% WC-10Ni coating at 200°C, 400°C, 600°C, and 800°C revealed that the lowest wear rate, 0.35 × 10-5mm3N-1m-1, occurred at 600°C, where the average friction coefficient was 0.432 and oxidative wear was predominant. At 800°C, the coating suffered significant damage, resulting in deteriorated wear resistance.