Study on influences of material micro-structure in micro-EDM by molecular dynamics simulation

Material micro-structure is one of the possible factors determining the limits of minimum machinable size in micro-EDM. In this paper, influences of anisotropy of single-crystal atomic structure on the forming process of discharge craters were investigated. Shape dimensions of discharge craters generated on the planes of {100} , {110} and {111} orientations were obtained from the results of the molecular dynamics simulation. It was found that the shape dimensions depend on the crystal orientation, and that the discharge craters were deeper in the order of {100} , {110} and {111} planes under the same discharge conditions. In addition, influences of micro defects like micro cracks and pores pre-existent in the workpiece material prior to occurrence of discharge on the forming process of craters were studied.