MODELLING OF MATERIAL REMOVAL IN ELECTROSTREAM DRILLING

Abstract

Electrostream drilling (ESD) process is gaining prominence in the machining of small holes in difficult to machine materials used in space, aviation, electronics and computers, medical, and automobile industries. This process employs a jet of charged acid electrolyte for anodic dissolution of workpiece material. As the trend towards miniaturization continues, this process has shown its superiority over other contemporary non- conventional micro and macro hole drilling processes. The major advantage of this process is to drill small holes having diameter range from 0.125 to 0.2 mm with large aspect ratio. The present work "Modelling of material removal in Electrostream drilling process" has been completed in two phases. In the first phase we develop a two-dimensional finite element model for the analysis of ESD process using quadrilateral (rectangular) elements. Dimensional analysis has been performed and a relationship between the radial overcut and ESD process parameters has been established. The developed model predicts the overcut and material removal rate. In the second phase a one dimensional analytical model has been proposed to determine the relationship between the material removal rate and working conditions (Applied voltage, IEG, electrolyte pressure and electrolyte properties), by considering the effect of void fraction alone and later considering the combined effect of electrolyte temperature along with void fraction. Finally, validation of proposed models has been done with the experimental results and a good correlation between predicted values from proposed models and experimental results has been observed