Abstract
A new nanoparticle plasma spray process has been developed that uses conventional powder feeders and injectors to produce fine ceramic coatings at high deposition rates. This paper explains how powder feedstocks are prepared and how the resulting coatings compare with coatings by other methods. The feedstock used in the demonstration was produced by adding YSZ nanoparticles to an acrylic liquid resin, which was then solidified, crushed, and screened. SEM images show that the nanoparticles are well dispersed throughout the resin fragments. In the plasma flame, the resin fragments burn down as the nanoparticles are heated and accelerated toward the substrate, producing fine zirconia layers free of microcracks and pores as observed by SEM. The presence of carbon deriving from the resin material is dealt with by post-process heating at different temperatures, the effect of which is assessed by means of thermogravimetry. Vickers hardness of the YSZ phase was measured to estimate the sintered density.
