Structure and properties of nanostructured ceramic matrix composite coatings prepared in-situ by reactive plasma spraying micro-sized Al-Fe2O3-Cr2O3 powders

Nanostructured FeAl2O4-based ceramic matrix composite coatings were prepared in-situ by reactive plasma spraying micro-sized Al-Fe2O3 and Al-Fe2O3-Cr2O3 powders. The microstructure, toughness, Vickers hardness, and adhesive strength of these coatings were investigated by X-ray diffraction, scanning electron microscopy, transmission electron microscopy and mechanical tests. The results indicated that both the coatings exhibited a nanostructured microstructure. The grains of coating AFC sprayed with Al-Fe2O3-Cr2O3 powders are finer than those of the coating AF sprayed with Al-Fe2O3 powders. The composite nano-coating sprayed with Al-Fe2O3-Cr2O3 powders exhibited higher hardness and better wear resistance compared with those of the composite nano-coating sprayed with Al-Fe2O3 powders. The adhesive strength, toughness, and wear resistance of the composite coating sprayed with Al-Fe2O3-Cr2O3 powders were significantly enhanced compared with those of the composite coating sprayed with Al-Fe2O3 powders, which were attributed to the Cr2O3 addition. (C) 2013 Elsevier Ltd and Techna Group S.r.l. All rights reserved.