Microstructure, Adhesion, and Erosion Wear of Plasma Sprayed Alumina–Titania Composite Coatings

ABSTRACT: Plasma spray technology is being widely used for the development of protective coatings to prevent degradation of critical components working under severe conditions. Plasma sprayed alumina–titania have many industrial applications. These coatings provide a dense and hard surface which is resistant to abrasion, corrosion, cavitation, oxidation, and erosion. Plasma sprayed alumina–titania coatings are regularly used for wear resistance, electrical insulation, thermal barrier applications, etc. Alumina pre-mixed with titania powder is deposited on mild steel substances by atmospheric plasma spraying. Microstructure of the coating is analyzed by SEM. Adhesion strength of alumina–titania coatings are measured. The response of plasma sprayed alumina–titania coatings to the impingement of solid particles has been presented in this study. The erosion rate is calculated on the basis of ‘coating mass loss’. It is observed that the erosion wear rate varies with erodent dose, angle of attack, the velocity of erodent, standoff distance, and size of the erodent. Cumulative coating mass loss varies with time of erosion. KEY WORDS: alumina–titania coating, plasma spraying, adhesion strength, solid particle erosion