Cold flame-sprayed and oil-impregnated porous metallic coatings

► The surface composition of the flame-sprayed coatings differs from that of the bulk, since the surface is depleted in Fe and enriched in B, C and Si. The alloy-forming metals are present on the coatings mainly in oxidised and hydroxidised states. ► Oil uptake and release are inversely related to the oxygen concentration at the surface of the coatings. ► The surface energy is dominated by the Lifshitz-van der Waals component of surface energy. ► Oil uptake and release are inversely related to the Lifshitz-van der Waals component of surface energy.