Effect of electrical pulse parameters on the machining performance in EDM

Abstract

In electrical discharge machining (EDM) material is removed through periodical electrical discharges between the tool and workpiece. The electrical discharge energy which is transformed into heat in the discharge zone is of key importance in EDM. The machining performance of EDM is defined by the characteristics of electrical discharge pulse. For these reasons, the principle of EDM and the characteristics of electrical pulse parameters are analyzed in this paper. Discharge current and pulse duration are selected as the most important electrical pulse parameters. In addition, their influence on material removal rate, tool wear ratio, gap distance and surface roughness are experimentally investigated. The experiments are conducted on an manganese-vanadium tool steel using graphite tool electrodes. The study allows efficient identification of relevant electrical pulse parameters, and the results obtained represent a technological knowledge base for the selection of optimal EDM machining conditions.