Molecular dynamics simulation of machining properties of polycrystalline copper in electrical discharge machining

In electrical discharge machining, the rapid heating and quenching effects cause the formation of resolidified layers, heat-affected zones, and defects, which have a tremendous impact on the mechanical properties of materials. Thus, to analyze the formation and evolution process of defect structures, single discharges in polycrystalline copper were simulated. The research results show that after a discharge, a larger number of stacking faults and dislocations existed in polycrystalline copper, which were mainly concentrated under the discharge crater and bulge. In these defects, the bedded stacking faults played a dominant role. Additionally, the results indicate that under the same discharge conditions, the diameter of the discharge crater in polycrystalline copper was larger than that in monocrystalline copper, whereas their depths were almost the same, and the volumes of both the bulge and removal debris generated in polycrystalline copper were larger than those generated in monocrystalline copper