Microstructure of Al2O3-13TiO2 coatings deposited from nanoparticles by plasma spraying

Abstract

The aim of the study was to characterize nanostructured Al 2O3-13TiO2 coatings deposited by plasma spraying on a grit blasted steel substrate. The Al2O 3-13TiO2 coatings were characterized using scanning and transmission electron microscopy and X-ray diffraction techniques. Obtained coatings possessed a unique microstructure consisting of fully melted regions with the microstructure similar to a typical plasma sprayed lamellar morphology as the conventional coatings and areas comprising unmelted or partially melted nanosized particles. The analysis showed that most of the αr-Al 2O3 phase from the nanostructured powders transformed into γ-Al2O3 phase after plasma spraying process. Moreover, the presence of amorphous phase was also observed.