Analysis of Thermal Barrier Plasma Coatings Based on Zirconium Oxide

Abstract

The literature on the zirconium oxide-based thermal barrier coatings over the past 25 years has been analyzed. Engineering criteria for analysis of the parameters of plasma spraying of oxide layers have been proposed. BRIEF modern oxide layers are formed in thermal barrier plasma coatings with defects: they are either porous or contain segmentation cracks perpendicular to the substrate. Three engineering criteria for analysis of these structures have been proposed: the effective plasma power, parameter of heating of a sprayed powder, and heat input. These criteria determine the temperatures of sprayed particles and coating, which affect the cohesive strength and structure of a coating. An increase in these criteria leads to an increase in the average number of segmentation cracks. Changing the variables in the relations for the effective power of the plasma jet, plasma gas flow rate, sprayed particle size, plasmatron movement rate, and spraying distance determines the effective power of the jet at this distance and the monolayer thickness.