摘要:The Electro Chemical Discharge Machining (ECDM) is a hybridization process of electro chemical and electric discharge machining, which is used for machining of hard, brittle and nonconductive materials. The present paper investigates the effect of duty ratio at different pulse frequency on the four process responses, i.e. material removal rate, depth of penetration, surface damage and heat affected zone of the hole drilled by ECDM. The requirements of a quality drilled hole are to have less surface damage and heat affected zone along with larger depth of penetration and material removal rate. The selected alumina ceramic (Al2O3) work piece material is widely used in hi-tech electrical apparatus. The results were characterized by optical microscope and analysed by using pulse wave forms of voltage with time. The results show that the effectiveness of pulse frequency varies according to the desired response characteristics. The research findings provide the most effective duty ratio for an improved quality of drilled hole in ceramics.