Parametric Investigation of Powder Mixed Electrical Discharge Machining of Al-Sic Metal Matrix Composites

Abstract – In recent few years composite materials have gained pace in engineering application. But they have poor machinability by using conventional machining methods. So it is required to study about these materials for better use in engineering application. To fulfillment of this aim, a study is done by conduct experiments (i.e. Machining) on Al/SiC metal matrix composite (MMC). From the non-conventional machining process, Powder Mixed Electrical discharge machining (PMEDM) is used to machining of Al/SiC MMC. PMEDM is a technological improvement in conventional EDM, which was previously studied by many researchers to better MRR with good surface roughness (SR). In this study, the controllable machining process parameters (i.e. Peak Current (Ip), Duty Cycle, Powder Concentration (PC), Gap Control and Sensitivity) of PMEDM was selected to experimental investigation. The process performance is measured in terms of material removal rate (MRR) and surface finish (SR). The research outcome will identify the important parameters and their effect on MRR of Al/SiC MMC in the presence of suspended graphite (Gr) powder in a kerosene dielectric of EDM. Response surface methodology (RSM) has been used to plan and analyze the experimental results. The experimental results emerged that only sensitivity has non-significant effect on MMR and SR from the selected process parameters, but it gives significant effects with other factors in interaction. Further it found that, the MRR is directly proportional to Ip and inversely proportional to the PC and duty cycle, and the SR improves at lower Ip and optimum range of PC, gap control and duty cycle.