Engineered YSZ Powders for High Power Plasma Spraying of Thermal Barrier Coatings

Air plasma spraying of yttria stabilized zirconia for thermal barrier coatings has been in use in gas turbines since the 1980's. YSZ powders currently in use 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 like 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 utilise 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 will look 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 evaluated for their microstructure, thermal properties as well as cyclic lifetime at high temperature.