Determination of multi-performance characteristics for powder mixed electric discharge machining of tungsten carbide alloy

Abstract

This article aims to develop a method that optimize the multi-performance characteristics, that is, micro-hardness and surface roughness of powder mixed electric discharge machining process. For experimentation, four input parameters—(a) pulse-on time, (b) pulse-off time, (c) current and (d) powder—are considered to investigate the improvement in multi-performance characteristics using Taguchi’s L27 orthogonal array design. Furthermore, to optimize these parameters and to handle the element of uncertainty associated with multi-input and discrete data, a method combining the grey and Taguchi experimental design was established. Theoretical prediction of results obtained from grey relational grade approach shows that the proposed approach proved useful for optimizing surface roughness and micro-hardness. In addition, analysis of variance is used to find the percentage contribution of process parameters. Finally, from analytical and experimental results, it is concluded that the pulse-on, powder and current are the most influencing parameters in powder mixed electric discharge machining of cobalt-bonded tungsten carbide.