Influence of Zirconia Powder Fractional Composition on Microstructure and Properties of Thermal Barrier Coating Obtained by Thermal Spraying

Abstract

Thermal spraying is one of the most promising methods for obtaining thermal barrier coatings for aerospace applications. Providing the necessary set of coating properties and their stable reproducibility are an actual task of the modern production. The purpose of this work was to determine the influence of the initial powders fractional composition on the structure and properties of the protective coating. The microstructure and the elemental composition features of the heat-resistant and ceramic layers of the thermal barrier coating are investigated. It is shown that the microstructure, porosity and microhardness of the coating ceramic layer depend on the ZrO2+8%Y2O3initial powder fractional composition. The porosity of the coating and the average pore size increase with increasing particle size of the powder. The maximum value of the ceramic layer microhardness is observed when using a powder fraction of 40-80 μm. The studies have found that microstructure and the necessary combination of coating physical and mechanical properties are achieved during the deposition of zirconia powder fractions 40-80 microns.