High speed abrasive electrical discharge machining of particulate reinforced metal matrix composites

A high speed abrasive electrical discharge machining (AEDM-HS) process has been developed to improve the performance and save the machining energy of the conventional EDM process in machining particulate reinforced metal matrix composites (MMCs). The AEDM-HS process functions under a combined action of spark erosion and direct mechanical grinding. A set of experiments was conducted and the results showed that the material removal rate (MRR) of AEDM-HS was much higher than that of EDM under the experimental conditions of this study. Moreover, the surface roughness value (Ra) measured for the AEDM-HS specimen was about six times smaller than that of the specimen machined without high speed abrasive action (i.e., EDM alone). The material removal mechanism of this novel process has been analyzed by means of single-pulse experimentation. And the relative importance of the various processing parameters on MRR was established using orthogonal analysis. The results showed that the MRR is influenced by the machining factors in the order of duty cycle > current > pulse duration. This study showed that the AEDM-HS process is superior to the EDM process for machining particulate reinforced MMCs, where a higher machining efficiency and a better surface quality can be obtained.