Abstract
In this work, in order to study the removal mechanism in the case of micro EDM workpiece, the ratio of removal by evaporation, g with regard to the total removal volume per pulse, V was obtained. Under an assumed value of g, the removal volume by evaporation, Vv is calculated based on the experimental result (V), and then compared with the simulated vaporization volume, Vvap. The value of g was varied until Vvap = Vv, whereby g is now equal to the ratio of removal by evaporation. However, main parameters to develop the temperature distribution model to obtain Vvap namely energy distribution ratio into micro EDM workpiece, X and plasma diameter, d are unknown. In this work, X is the summation of ratio of energy conducted within workpiece and ratio of energy carried away by debris which is also in the function of g. Thus, X was first fixed by assuming the value of g. After igniting a single pulse discharge on a Cu workpiece and the crater diameter, dm was measured, the model of temperature distribution in workpiece was developed and the simulated molten area diameter, dc was compared with dm. During simulation d were varied until dc = dm where d is now equal to the plasma diameter. Accordingly, using the simulated model, Vvap was calculated to be compared with Vv to obtain g.
