Engineers from Treibacher Industrie AG, Austria, presented a discussion titled “Engineered YSZ Powders for High Power Plasma Spraying of Thermal Barrier Coatings” at the ASM International ITSC 2019 conference. Air plasma spraying of yttria stabilized zirconia for thermal barrier coatings has been used in gas turbines since the 1980’s. Current YSZ powders were originally developed together with the plasma spray equipment then available. In the decades since, the demands for ever-higher performance have pushed coating equipment and materials to the limit to achieve goals such as higher porosity levels, lower conductivity, and longer lifetime.
In recent years, high-power plasma spray equipment has become available that allows greater efficiency and materials throughput than legacy equipment. In order to utilize the extra capabilities of these newer systems, a new generation of YSZ powders has been developed with properties and structures engineered for the final coating requirements.
This study looked at the comparison between the newly developed powders and conventional powders used to produce a range of TBC types; from dense segmented coatings to high porosity coatings. The coating process with high energy plasma equipment will be evaluated for deposition efficiency as well as deposition rate. Finally, the thermal barrier coatings are to be evaluated for their microstructure and thermal properties, as well as cyclic lifetime at high temperature.
Authors: Dr. Nicholas Curry, Mr. Matthias Leitner, Mr. Karl Korner, Treibacher Industrie AG, Althofen, Austria
