Abrasion, Erosion and Cavitation Erosion Wear Properties of Thermally Sprayed Alumina Based Coatings

Thermally-sprayed alumina based materials, e.g., alumina-titania (Al2O3-TiO2), are commonly applied as wear resistant coatings in industrial applications. Properties of the coatings depend on the spray process, powder morphology, and chemical composition of the powder. In this study, wear resistant coatings from Al2O3 and Al2O3-13TiO(2) powders were sprayed with plasma and high-velocity oxygen-fuel (HVOF) spray processes. Both, fused and crushed, and agglomerated and sintered Al2O3-13TiO(2) powders were studied and compared to pure Al2O3. The coatings were tested for abrasion, erosion, and cavitation resistances in order to study the effect of the coating structure on the wear behavior. Improved coating properties were achieved when agglomerated and sintered nanostructured Al2O3-13TiO(2) powder was used in plasma spraying. Coatings with the highest wear resistance in all tests were produced by HVOF spraying from fused and crushed powders.