Parametric optimization of electric discharge coating on Aluminium-6351 alloy with green compact silicon carbide and copper tool: A Taguchi coupled utility concept approach

Abstract

In this article, an attempt has been made for optimizing the process parameters of Electro Discharge Coating (EDC) on Aluminium-6351 alloy using SiC/Cu green compact tool by the application of utility concept of Taguchi method. A set of best possible combination of process parameters like compaction load, tool composition, current and pulse on time on two output parameters such as micro hardness and surface roughness has been developed. The experiments are designed based on L16 orthogonal array. The analysis of means (ANOM) is used to determine the optimal level of the process parameters and analysis of variance (ANOVA) is used to identify the relative importance among the process parameters. The ANOVA results shows that the most important process parameter is pulse on time followed by current, compaction load and tool composition which affects the optimization of the output parameters. Based on the optimal levels of process parameters, a confirmation test has been carried out to explain the effectiveness of the Taguchi optimization technique. The highest micro hardness of 301μm and the surface roughness of 2•63μm are successfully obtained. Moreover, to confirm the presence of tool materials on the workpiece surface, XRD, SEM, EDX and also optical microscopic image analysis have been carried out.