Dense nanostructured YSZ coating prepared by low-pressure suspension plasma spraying: Atmosphere control and deposition mechanism

Suspension plasma spraying (SPS) has attracted more and more attention in terms of the preparation of nanostructured ceramic coatings. However, due to the low mass of the nanopowder, it is challenging to prepare high-density coatings through SPS, and this largely limits its application in the areas such as electrolytes of solid oxides fuel cell (SOFC) and environmental barrier coatings. In this article, a novel suspension spraying technology - low-pressure suspension plasma spraying (LPSPS) - was used to prepare a high-density, nanostructured coating. The results revealed that the environment atmosphere (inert atmosphere versus oxidative atmosphere) played a critical role in the microstructure of the coating. The deposition mechanisms of the coatings in both atmospheres were proposed, and a high-density nanostructured yttria-stabilized zirconia (YSZ) coating was successfully prepared by atmosphere control, based on these deposition mechanisms.