Microstructure and Microhardness of Alumina-3wt. % Titania Coating Formed by a New Multi-Chamber Gas-Dynamic Accelerator

Alumina-titania coatings are widely used in industry for wear, abrasion or corrosion protection components. This paper presents the results of the investigation of the structure and microhardness of the alumina-titania (Al2O3:Ti wt ratio = 97:3) coating was prepared by a new multi-chamber gas-dynamic accelerator on corrosion-resistant steel substrate. Morphology of the powder particles, microstructure and phase composition of the coating were characterized with the use of scanning electron microscopy, X-ray phase analysis and Vickers hardness tester at a test load 0.2 kg. The results show that the microstructure of the alumina–3wt.% titania coating consists of region with different degrees of melting: the lamella built up from the fully melted particles of the powder, and partially melted regions. The developed coating by this method is highly dense (porosity of less than 0.2%) and tightly adherent.