Influence of powder size distribution and heat flux on yttria stabilised coatings elaborated by liquid suspension injection in a DC plasma jet

摘要

This paper is devoted to the study of coatings elaborated by a process permitting Air Plasma Spraying (A.P.S.) of finely structured ceramic coatings. This process mainly consists in injecting in a d.c. plasma jet, a ceramic suspension containing sub-micron ceramic particles. Coating characteristics are close to those observed in P.E.C.V.D., but with a faster elaboration rate (≈15μm/m{sup}2.h) and, the possibility to produce a wide range of thicknesses (1 < e < 100μm). This paper is aimed at producing the Yttria Stabilized Zirconia electrolyte (Y.S.Z.) of Solid Oxide Fuel. Cells with a thickness of 5 to 30 μm. Previous studies of this process have been devoted to the influence of the spray parameters on the structure of Y.S.Z. splats collected and have allowed determining some well adapted working conditions. The new stage described in this paper, is related to the study of the growth of Yttria Stabilized Zirconia coatings and the influence of different parameters such as the ceramic particle size distributions contained in the suspension and the heat flux imposed to the surface of the substrate and successive passes during the coating elaboration.