Abstract
The aim of this study is to develop for thermal barrier applications a new process in which coatings exhibit properties between those of APS and EBPVD. This process includes two conventional D.C. plasma torches working in a chamber whose pressure can vary between 30 and 100 kPa. Micro-sized yttria stabilized zirconia powders are injected in both plasma jets to vaporize them, at least partially, and produce finely-structured coatings from vapor and micro-droplets deposition. The torch arrangement allows separating the vapor and the very small particles (less than 1 µm) from the partially vaporized bigger ones. The diagnostics are based on optical emission spectroscopy, pyrometry, imaging of particles trajectories and coating microstructural characterization.
