Surface modification of ZrO2-10 wt. % CaO plasma sprayed coating

Abstract

Oxide ZrO2-CaO plasma-sprayed coatings were remelted using the modified gas tungsten arc welding (GTAW) method. The original two-burner set, generating a free independent arc, was used in the treatment. The samples were subjected to structural examination using light and scanning electron microscopes, and energy-dispersive X-ray microanalysis (EDX). A substantial heterogeneity of the plasma-sprayed coatings was found, observable with a laminar structure, significant porosity, and step change in the concentration of the elements. Significant changes in the structure were found after the remelting treatment. Both microscopic and EDX investigations showed that the treatment leads to a reduction in the heterogeneity of the chemical composition of the coating material and to a loss of structural characteristics typical for plasma-sprayed coatings.