Evaluation of Wear Resistance of Plasma Sprayed Ceramic Coatings

Various ceramic coatings based on yttria stabilized zirconia (YSZ), deposited by atmospheric plasma spraying technique on stainless steel substrates were studied for investigation of their tribological behaviour. Materials selected for this investigation were tetragonal zirconia and alumina. The wear properties of plasma sprayed coatings were investigated by sliding test under conditions of dry contact with reciprocating and scratch test. To identify the wear mechanism, optical and scanning electron microscopes, surface roughness tester and scratch tester were used. Alumina-zirconia composite coatings with 15 wt. % and 85 wt. % of alumina exhibited improved wear resistance under unlubricated conditions. Microstructural characterization of the worn surfaces was performed and the wear of coated surfaces was explained in terms of their morphology. The wear resistance under dry conditions for plasma-sprayed ceramic coatings was determined by the composition of the material. Morphological study of worn surfaces indicated that abrasion is dominant mechanism of wear investigated.