Effect of powder concentration on the EDM performance of AISI 304 using cryotreated post tempered electrodes

Abstract

Powder mixed electro discharge machining (PMEDM) is a hybrid machining process in which dielectric fluid is mixed with electrically conductive powder particles for enhancing surface quality and material removal rate. Cryogenic treatment was brought in this process to improve tool life and cutting tool properties. In this research, silicon carbide (SiC) powder mixed electro discharge machining (EDM) has been performed for AISI 304 machining. Experiments have been carried out to study the effect of powder concentrations (0 g/l, 4 g/l, 6 g/l, 8 g/l and 10 g/l) on the EDM performances viz. radial overcut (ROC), material removal rate (MRR), surface roughness (Ra) and tool wear rate (TWR) using three tungsten carbide electrodes (i.e. untreated, cryotreated single and double tempered). With addition of powder concentration material removal rate, radial overcut enhances and surface roughness and tool wear rate reduces. With the addition of powder concentration MRR, TWR, Ra and ROC decreased up to 10.60%, 37.08%, 15.95% and 9.31% for cryotreated single tempered electrode and decreased up to 16.64%, 42.10%, 26.58% and 12.19% for cryotreated double tempered electrode respectively. Microstructural analysis of machined surface has been carried out for the PMEDMed surfaces.