Role of SiC nanoparticles on tribological properties of atmospheric plasma sprayed 5 wt% SiC–Ni60 coatings

Abstract In order to comparatively investigate the role of SiC nanoparticles on tribological properties under dry and water-lubricated conditions, Ni60 and 5 wt% SiC–Ni60 coatings were deposited by atmospheric plasma technology. The morphologies and phase composition of coatings were inspected by scanning electron microscopy and X-ray diffraction, respectively. And friction interface of coatings was examined by X-ray photoelectron spectroscopy and high-resolution transmission electron microscope to reveal the wear mechanisms of coatings after friction. Results illustrated that SiC nanoparticles could function as reinforcing phases, inducing friction-reducing and anti-wear. And tribological properties of 5 wt% SiC–Ni60 coating under dry and water-lubricated conditions were superior to those of Ni60 coating. The analysis of worn surface revealed that SiC nanoparticles could fill pits on the surface of coatings. According to FIB-TEM analyses and XPS results, SiC nanoparticles released onto friction interface can undergo hydrolysis reaction under water-lubricated condition, and the film containing SiO2 is formed by the hydrolysis reaction of SiC nanoparticles, which improves good boundary lubrication effect.