Electro-Thermal Modelling for Material Removal Study in Electric Discharge Machining Process

In the present study, an attempt has been made to model the electric discharge machining process using the numerical simulation technique. Realistic parameters are added in the model such as variable fraction of heat going to the electrodes, and variation in the plasma flushing efficiency with the process parameters. Gaussian distributed heat flux is applied at the spark location and the two-dimensional heat conduction equation is solved with the help of finite element analysis technique to determine the temperature distribution within the two-dimensional process continuum, using averaged thermo-physical properties of the work material. Melting isotherms are determined and the material removed during a single discharge is obtained from it. Material removal rate is determined using a regression model for the plasma flushing efficiency. Experimental validation is made with the help of highly precise AGIE SIT experimental data. The material removal rate is also compared with state of the art research of other researchers. It has been observed that, at low value of the discharge energies, the proposed model is able to predict the experimental material removal rate better than that of the model proposed by other researchers. However, as the discharge energy increases, the accuracy of prediction decreases. The model can be used for achieving process parameter optimization hence saving both the costs and large lead times associated with determining optimized parameters experimentally.