Oxidation resistance of ceramic coatings treated by impulse plasma fluxes

摘要

(ZrO{sub}2-Y{sub}2O{sub}3)-NiCrAlY two-layer coatings were sprayed by impulse plasma method in air and then were treated by impulse plasma fluxes in vacuum. It was established that the oxidation process after an impulse plasma treatment is decelerated by 1,5 to 1,7 times. It is connected with the reduction of open porosity on the treated surface ceramic layer. ZrO{sub}2 large crystals with horizontal-plane structure are formed and residual stresses are reduced during an impulse plasma treatment. The destruction of coatings was resulted from formation of (Ni, Al){sub}xO{sub}y scale on the boundary of heat-resistant alloy-thermobarrier layer.