Developing empirical relationships to estimate porosity and Young's modulus of plasma sprayed YSZ coatings

Plasma spraying process is an effective thermal spray process to deposit thermal barrier coatings (TBCs) on the components of propulsion and land based gas turbines to enhance its performance. In this work, empirical relationships were developed to estimate TBCs performance characteristics (porosity and Young's modulus) of yttria stabilized zirconia coatings by incorporating independently controllable atmospheric plasma spray operational parameters (input power, standoff distance and powder feed rate) using response surface methodology (RSM). A central composite rotatable design with three factors and five levels was chosen to minimize the number of experimental conditions. Within the scope of the design space, the input power and the standoff distance appeared to be the most significant two parameters affecting the coating quality characteristics among the three investigated process parameters. Further, correlating the spray parameters with coating properties enables identification of characteristics regime to achieve desired quality of YSZ coatings.