PREDICTION OF SURFACE ROUGHNESS, MATERIAL REMOVAL RATE AND TOOL WEAR RATIO MODELS FOR SIC POWDER MIXING EDM

Abstract

Powder mixed electric discharge machining (PMEDM) is one of the new innovations for the enhancement of capabilities of the electric discharge machining process. This paper is an attempt to study the effect of SiC powder mixed in the kerosene dielectric fluid. The type of electrodes, the peak current and the pulse-on time are the main selected EDM input parameters. The workpiece and the electrodes materials are the AISI D2 die steel and copper and graphite materials, respectively. The output responses considered are the workpiece surface roughness (SR), the material removal rate (MMR) and the tool wear ratio (TWR). The experiments are planned using the response surface methodology (RSM) design procedure. Empirical models are developed for SR, MRR and TWR using the analysis of variance (ANOVA) and regression models to study the effect of process parameters. The best results for the productivity of the process (MRR) were obtained when using graphite electrodes at pulse current (22 A), pulse on duration (120 μs) and with silicon carbide (SiC) powder mixing in kerosene dielectric at reaches (76.76 mm³/min). These results improved the material removal rate by (264%) with respect to the corresponding value obtained when using copper electrodes with kerosene dielectric alone. The best (TWR) results of the process were obtained when using graphite electrodes at pulse current (8 A), pulse on duration (40 μs) and using the kerosene dielectric alone reduced to the level (0.1023 %)...