LAUSR

Abstract Graphite-modified Al2O3 coatings were deposited on a P265GH steel by atmospheric pressure plasma spraying. The influence of graphite concentration in the feedstock powders, relating to the surface morphology, elemental composition and phase structure of the coatings was characterized by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX) and X-ray diffraction. The tribological properties of the as-sprayed coatings were determined under dry-sliding conditions. It was obtained that the graphite particles were homogeneously distributed on the surface of the coatings. The graphite concentration was 1.6 wt%, 2.4 wt% and 3.1 wt%, when the amount of graphite in the feedstock powders was 5 wt%, 10 wt% and 15 wt%, respectively. The addition of graphite reduced the friction coefficient of the composite coatings down to 0.53; which was ∼30% and ∼18% lower, compared to steel and the Al2O3 coatings, respectively.