Experimental and numerical investigations of machining depth for glass material in electrochemical discharge milling

Electrochemical discharge milling (ECDM) is one of the best alternatives for microchannel fabrication in non-conducting materials. The ECDM is a complex process which makes difficult the prediction of the material removal rate (MRR). The prediction of the machining depth in the microchannel fabricated with electrochemical discharge milling (ECD milling) was an interesting research subject. This study attempts to present a thermal model based on the finite element method (FEM) to predict the machining depth in ECD milling. The input parameters of the FEM model were calculated based on different machining conditions such as machining voltages and electrolyte concentrations. The model is validated by conducting experiments in the same ECD milling conditions. In the FEM model, the different criteria for the material removal temperature (Teq) were applied and the machining depths were calculated. The comparisons of the results show that there is good agreement between FEM models and experimental results when the Teq were selected between 600 to 850 °C. It seems that the softening Littleton point of 720 °C is a good suggestion as a criterion for the material removal temperature in ECD milling.