The effect of deionisation time on the electrical discharge machining performance

An experimental and numerical study to evaluate the time needed for dielectric deionisation between consecutive discharges as well as its effect on performance of electrical discharge machining was done. In the numerical study, the open voltage (gap width definition), current intensity, discharge duration and discharge interval were used among the large number of input parameters used experimentally in the process of electrical discharge machining. The performance parameters values, as well as the time needed for a complete deionisation of the dielectric liquid using a finite element model were calculated. In the numerical study, the time needed for the complete deionisation of the dielectric liquid was calculated using the condition that the temperature reached in the boundaries of the plasma channel with the electrodes has a value between 6,000 and 4,500 A degrees C. In the experimental study, the researchers acquired the time needed for the complete deionisation of the dielectric liquid using small discharge duration and a discharge interval variable between the minimum acceptable by the control of the machine and the one that causes a significant decrease in the material removal rate. The numerical results are in agreement with the experimental data.