Effect of Heat Treatment of the Alumina Powder on the Microstructure and Properties of Coatings

The alumina powder was treated at a high temperature (1000°C). Dense (porosity of less than 2%), solid (1280 ± 30 HV0.3) and wear-resistant coatings based on heat-treated alumina powder were obtained by a multi-chamber detonation sprayer on the steel substrate. The microstructure, microhardness and the wear resistance of the alumina coatings were investigated.