Process Analysis and Monitoring in WDM Using FEM Approach

Abstract

A thermal–electrical model was developed for sparks generated by electrical discharge in a liquid media (kerosene). A single spark has been used for the discharge channel created between the electrodes. The discharge channel being an electrical conductor will dissipate heat, which is taken as Gaussian heat source. The amount of heat dissipated varies with the thermal–physical properties of the conductor, as a result the maximum temperature reached is different. In the present model, the heat flux is taken as a function of radii value of the conductor and directly proportional to the current, breakdown voltage and fraction of heat input to work piece. In this work, the study of mechanism of material removal in die steel with emphasis on AISI D2 die steel, with copper tool is carried out using Finite Element Method. Temperature distribution within zone of influence of single spark is obtained with the application of finite element method (FEM). The nodal temperatures obtained by FEM are further post processed for estimating MRR. The ANSYS 11.0 software has been employed to model the problem and the same is used to evaluate the temperature distribution. An attempt has been made to find the material removal rate from the FEM model. Further experiments have been carried out to validate the results obtained by the developed FEM model for different values of current, pulse on time and pulse off time.