Experimental investigation of powder-mixed electric discharge machining of AISI P20 steel using different powders and tool materials

Purpose The purpose of this paper is to investigate the performance of powder-mixed electric discharge machining (PMEDM) using three different powders which are aluminium (Al), silicon carbide (SiC) and aluminium oxide (Al2O3). Besides that, the influence of different tool materials was also studied in this experimental investigation. Hence, the work material selected for this purpose was AISI P20 steel and tool materials were copper, brass and tungsten. The performance measures considered in this work were material removal rate (MRR), tool wear rate and radial over cut (ROC). Design/methodology/approach The process variables considered in this study were powder types, powder concentration, tool materials, peak current and pulse on time. The experimental design, based on Taguchi's L-27 orthogonal array, was adopted to conduct experiments. Significant parameters were identified by performing the analysis of variance on the experimental data. Findings Based on the analysis of results, it was observed that copper tool combined with Al powder produced maximum MRR (58.35mm(3)/min). Similarly, the Al2O3 powder combined with tungsten tool has resulted least ROC (0.04865mm). It was also observed that wear rate of tungsten tool was very low (0.0145mm(3)/min). Originality/value The experimental investigation of PMEDM involving three different powders (Al, SiC and Al2O3) was not attempted before. Moreover, the study of influence of different tool materials (Cu, brass and W) together with the different powders on the electric discharge machining performance was very limited.