Investigation of nanostructured and conventional alumina–titania coatings prepared by air plasma spray process

Nanostructured and conventional alumina–13 wt.% titania powders were thermally sprayed using air plasma spray (APS) process. Scanning electron microscopy (SEM) was used to examine the morphology of the agglomerated powders and the cross-section of the alumina–titania coatings. The microstructure and phase composition of the coatings were characterized by X-ray diffraction (XRD), and scanning electron microscopy (SEM). The fatigue and mechanical properties of the coatings were investigated. SEM analysis was also carried out on the worn surfaces of conventional and nanostructured coatings following the wear test. The experimental data indicated that the nanostructured coated samples exhibited higher hardness, wear resistance and fatigue strength compared to the conventional coated samples.