Optimizing the plasma spray process parameters of yttria stabilized coatings on AISI 316 Austenitic stainless steel using response surface methodology

Author(s): I. Nazimudeen, B. Kumaragurubaran , T. Senthilkumar

Abstract: Atmospheric plasma spraying is used extensively to make Thermal Barrier Coatings of 5-7% yttria-stabilized zirconia powders. The main problem faced in the manufacture of yttria-stabilized zirconia coatings by the atmospheric plasma spraying process is the selection of the optimum combination of input variables for achieving the required qualities of coating. This problem can be solved by the development of empirical relationships between the process parameters (current, powder feed rate, stand-off distance ) and the coating quality characteristics (coating thickness, coating hardness and porosity) through effective and strategic planning and the execution of experiments by response surface methodology. This article highlights the use of response surface methodology by designing four factor five level central composite rotatable design matrixe with full replication for planning, conduction, execution, and development of empirical relationships. Further, response surface methodology was used for the selection of optimum process parameters to achieve desired quality of yttria-stabilized zirconia coating deposits on stainless steel.