Research into Morphology and Properties of TiO2 – NiAl Atmospheric Plasma Sprayed Coating

Abstract

Titania (TiO 2) based coatings are ceramic products with unique properties that make them widely applicable (e.g. in automotive industry, optoelectronics, chemical pro-cessing or medicine). Atmospheric plasma spray process enables to deposit TiO 2 with addition of NiAl feedstock material which has an influence on coating cohesion and adhesion to substrate. However, the literature and technical notes give little informa-tion about parameters of spraying of TiO 2 -10 wt.% NiAl feedstock powders enables producing coating without nonuniformities including cracks and delamination form substrate. The aim of the work was to verify the parameters of plasma spraying by evaluation of the morphology and properties of manufactured the TiO 2 -10 wt.% NiAl coatings. Titania based coatings were deposited by means of atmospheric plasma sprayed on steel substrate using TiO 2 -10 wt.% NiAl feedstock powders. Morphology and microstructure were examined using light optical microscope (LOM) and scan-ning electron microscope (SEM). Coating chemical composition were analysed by means of SEM-EDS method. Coating surface topography and Knoop microhardness were determined. Porosity and thickness were evaluated by using quantities image analysis programme. Plasma spraying parameters used in our research allow to obtain uniform coating without cracks and delamination at coating-substrate interface. It ac-knowledges that uniformity of coating technological properties as well manufactured coatings can be put to wear tests, such as high temperature oxidation, corrosion, ero-sion or cavitation erosion resistance evaluation.