Mechanism of spark generation during electrochemical discharge machining: A theoretical model and experimental verification

The use of the electrochemical discharge phenomenon to machine materials is a very recant technique in the field of non-conventional machining. When the machined material is electrically conducting, the process is usually termed 'electrochemical are machining' (ECAM), whereas for non-conducting work materials it is termed 'electrochemical dischage machining' (ECDM). Although in both cases electical discharge takes place through the electrolyte and plays a critical role, the mechanism of spark generation has not been investigated adequately. In the present work a theoretical model of this discharge phenomenon is developed. With the help of the model, the critical voltage and current required to initiate discharge between the electrode and the electrolyte an estimated. The theoretically-predicted values compare quite well with experimental observations.