Prediction of white layer thickness and material removal rate in electrical discharge machining by thermal analyses

Electrical discharge machining (EDM) is one of the best alternatives in machining of electrically conductive materials. However, recast or white layer formation is either unwanted or inevitable output of EDM processes. On the other hand, material removal rate (MRR) can be slow and its prediction is difficult in that process. Therefore, exact determination of these outputs is critical for EDM performance. In this study, white layer thickness and material removal rate were predicted by using a theoretical thermal model and 3D finite element (FE) model. Numerical solutions of these models were compared with results of an experimental study. When compared to thermal model, finite element analysis (FEA) produced in good agreement with the experimental results. Errors of mean results are 1.98% and 3.34% by FEA in prediction of white layer thickness and material removal rate respectively.