Experimental Investigations on Ecdm Process Improvement While Machining a 1203

Advanced engineering ceramics which are widely used as high strength refractory material for several industrial applications, always pose a challenging opportunity to machine them. Conventional methods of machining are difficult to shape them because of their high hardness and brittleness, while grinding is the only popular method to machine them, but shaping of ceramics in desired form is difficult. Ceramics are generally electrically non conductive in nature and because of this reason, efficient processes like electrochemical machining (ECM) and electric discharge machining (EDM) can not be utilized to machine them. Though, some of the non traditional machining processes have ability to machine them, but the important aspects like material removal rate, diametric overcut, surface integrity, heat affected zone, etc. of the machined surface make them unsuitable most of the times. To cope up with such kind of problems, hybrid machining processes (HMP) are now being developed to make use of combined or mutually enhanced advantages of different processes for efficient and economical machining. In this trend of I-IMP, Electro Chemical Discharge Machining (ECDM), which combines the characteristics of electrochemical machining (ECM) and electric discharge machining (EDM), has shown potential to machine electrically conductive materials at a rate of 5 to 50 times higher than ECM / EDM (especially while working with suitable range of the parameters). This process has also shown the possibility to machine electrically non conductive materials like ceramics, quartz, glass, composites, etc. while using different machining techniques such as grooving, slicing, engraving, 3 D micro structuring, etc. Machining of ceramics in the form of drilling hole on A1203 and SiC by ECDM process show poor performance (material removal rate reduces gradually with machine time and finally stop) which leads to low machined depth and high tool wear. While at greater value of machined depth, abrupt nature of electrical discharge leads to micro crack on the machined surface due to high voltage. Due to such reasons, efficiency of the process is low especially while machining ceramics. To sort