Optimization of plasma spray process variables to attain the minimum porosity and maximum hardness of the LZ/YSZ thermal barrier coatings utilizing the response surface approach

Abstract Lanthanum zirconate (LZ) has emerged as a novel thermal barrier coating (TBC) material because of its higher temperature phase stability, and low sintering ability than the current standard yttria-stabilized zirconia (YSZ). In order to combine advantages, LZ YSZ feedstock powders are blended with predetermined weight ratios (50:50) composite coatings. The leading issue in developing using atmospheric plasma spray method (APS) is finding optimum range input parameters attain desired properties. This can be resolved by empirical relations find porosity microhardness (APS). Spray such power, distance, powder feed rate vital determining quality. Three variables five levels central rotatable design (CCD) reduce overall run experiment were utilized research. predicted specimens APS process parameters, examined through ANOVA. Optimizing was done response surface methodology (RSM), which provides minimum maximum hardness. It validated graphs, contour plots, overlay plots. As result, power greatest impact on properties among three variables, standoff distance subsequent important parameters.