Experimental investigations into ECSD process using various tool kinematics

Machining of electrically non-conducting materials, i.e. ceramics, composites, etc., is still a major problem. Electrochemical spark machining (ECSM) is found to be a potential process for machining these materials. However, ECSM has its own inherent problems too. So far, only non-rotational tools with gravity feed have been used by previous researchers, but the performance of such tools has been reported to be poor. In the present work, electrochemical spark drilling (ECSD) experiments have been conducted using various tool kinematics with a view to enhancing the process capabilities. Use of a rotational tool with controlled feed has been found to improve the process performance. Significant improvement in the "limiting value" of the machined depth during ECSD has been observed while using a tool with orbital motion. Geometrical parameters and surface integrity of the machined specimens have also been studied and presented. (C) 1997 Elsevier Science Ltd.