18. Numerical Simulation of Micro-EDM Process by Incorporating a Novel Approach of Multi-sparks

Due to the stochastic nature of the EDM process, limited knowledge of material removal mechanism as well as the progression of sparks is available. For complete utilization of the micro-EDM process, a concrete study is needed to understand the physics associated with the process such as the formation of crater, multiple-sparks generation, and overlapping of craters for uniform material removal. The scarcity of the models to simulate multi-sparks with appropriate crater overlap in the micro-EDM process is the motivation for the present work. This work presents a numerical simulation of the micro-EDM process based on the generation of multiple-sparks. The sparks are assumed to be occurring at a point of minimum inter-electrode gap (IEG) based on the arbitrary surface roughness assigned to the tool as well as the workpiece. Using the thermal ablation model as a mechanism of material removal and adopting Gaussian distribution of input heat flux to the workpiece, the crater radius, depth, and pulse frequency are determined by creating single sparks. The data obtained from the simulation of the single spark has been applied to develop a multi-spark approach for the removal of a single layer of material from the workpiece. The sparks are generated uniformly across the tool–workpiece contact length with appropriate crater overlapping.