Finite Element Modeling for Analyzing Material Removal Rate in ECDM Process

Electrochemical discharge machining (ECDM) has been developed as a hybrid and robust technology for machining non-conductive work material at a preferable removal rate. ECDM exhibits various applications in the micro-machining of these materials like nuclear, automotive, medical industries, etc. Due to some peculiar properties of nonconductive materials, for example, glass transparency, their utilization in MEMS applications are also very numerous. In the ECDM process, removal of material takes place primarily due to high-temperature thermal erosion and secondarily due to electrolyte chemical etching action. Many rigorous experimental studies have reported in the empirical estimation of the material removal rate (MRR) in the ECDM process. However, very few studies have reported in the modeling of the ECDM process for predicting material removal rate through single spark simulation. The present paper attempts to develop a transient thermal model based upon finite element modeling (FEM) to simulate a single spark in the ECDM process for obtaining temperature fields in the work material. The obtained temperature fields are further post-processed to predict the material removal rate. FEM results are compared with the previous simulated and experimental results to confirm the approach. Moreover, an experimental study is also performed to validate the developed thermal model and it was found to be in an acceptable range of the experimental results. Further, a parametric study revealed that MRR increases with the increase in applied voltage and electrolyte concentration during soda-lime glass machining with ECDM. The developed FEM-based transient thermal model can be successfully utilized for predicting the removal rate of nonconductive work material.