Properties of Alumina-Titania Coating Formed by a New Multi-Chamber Gas-Dynamic Accelerator

Thermal-sprayed alumina–titania coatings (Al2O3:Ti wt ratio = 60:40) were prepared by a new multi-chamber gas-dynamic accelerator. The coatings were examined by using scanning electron microscopy, X-ray phase analysis and Vickers hardness tester at a test load 0.2 kg. The coating was well-adhered with corrosion-resistant steel substrate. The results show that the microstructure of the alumina–titania coatings consists of areas with different degrees of melting: the lamella built up from the fully melted particles of the powder, and partially melted areas. The developed coating is highly dense (porosity is less than 0.7%). Research results show that hardness of alumina–titania coatings (Al2O3:Ti wt ratio = 60:40) can achieve up to 655 HV0.2 and the specific wear rate of alumina-titania coatings is 52.40∙10-5 mm3 (m∙N)-1.