The electrical discharge machining process aided by abrasive jet

Abstract

The purpose behind this work was the development of a hybrid methodology, which combines the electrical fischarge machining (EDM) with a high-pressure jet of dielectric fluid mixed with abrasive powder. The low MRR (material removal rate) observed on the EDM is, undoubtedly, one of the most important limitations of this process, especially today, where competitiveness among the enormous varieties of machining processes has attained an unbelievable level of speed and surface finishing. A special device was built in order to provide and apply the high-pressure abrasive jet. Cooper tube-shaped tools were used for the experiments and the machined material consisted of commercial high-speed steel (AISI M2). Kerosene, deionized water, and mineral-based oil were used as dielectric fluids and the abrasive was constituted of SiC (600 mesh), with jet pressures varying from zero to 100 bar, and abrasive concentration kept fixed at 30 g/l. The results show an eightfold increase in MRR when the EDM process is aided by abrasive particles. Furthermore, remarkable gains were obtained with kerosene and deionized water, both with enhanced surface finishing. Therefore, this new process, denominated as abrasive jet electrical discharge machining (AJEDM), proves to be efficient for increasing machining velocity while decreasing the surface roughness and its use has shown itself to be technically viable.