Optimization of PVD process parameter for coating AZ91D magnesium alloy by Taguchi grey approach

This study was an attempt made to explore the possibility of increasing the surface properties of the AZ91D magnesium alloy by applying ZrO2 coating using Physical Vapour Deposition (PVD-RF) sputtering process. In order to improve the quality of the coating, the PVD process parameter with multiple performance characteristics was optimized by using the Taguchi grey approach. L18 orthogonal array was selected for conducting the experiments. The proposed Taguchi grey method was find out the optimal process parameter for multiple performance characteristics. The optimal combination was attained at chamber pressure of 0.003 bar, argon gas in millibar and power input of 200 W. The validation experiment result shows an improvement in the micro hardness and surface finish. Also, the performance characterizations such as SEM, EDX, XRD, coating thickness, surface roughness and micro hardness were measured at optimal process parameter.