Effects of the powder manufacturing method on microstructure and wear performance of plasma sprayed alumina–titania coatings

Three Al 2O 3–13wt.% TiO 2 powders, with the same chemical composition but different Al 2O 3–TiO 2 distribution patterns, are plasma sprayed and the resulting coatings are compared in terms of their phase composition, microstructure, hardness, crack growth resistance, and abrasive wear performance. It is demonstrated that the degree of mixing of the Al 2O 3 and TiO 2 ingredients in the feed powder has immense impact on the phase composition, microstructure, hardness, crack growth resistance, and abrasive wear performance of the coatings. A high degree of mixing of Al 2O 3 and TiO 2 in the powder state results in more uniform microstructure, higher hardness, higher crack growth resistance, and consequently better abrasive wear resistance of the coating.