Microstructural transformations of TiO2, Al2O3+13TiO2 and Al2O3+40TiO2 at plasma spraying and laser engraving

The paper deals with the investigation of microstructure of plasma sprayed and laser engraved coatings of TiO2 and Al2O3–TiO2 of two compositions (13 and 40 wt.% TiO2). The samples preparation technology includes also grinding and polishing prior to laser treatment. Transformations of crystal phases, present in initial powders, at all technological steps were investigated using X-ray diffraction (XRD) and Raman spectroscopy. Quantitative chemical analysis was carried out using X-ray photoelectron spectroscopy (XPS). Finally, morphology of powders and coatings surfaces and sections were investigated using scanning electron (SEM) and optical microscope (OM).