Comparison of EDG, Diamond Grinding, and EDM Processing of Conductive Alumina Ceramic Composite

Abstract

The ceramic materials are widely used in various industrial applications nowadays as they possess excellent properties like high hardness, low fractural strength, and brittleness, which makes machining very difficult and costly. Therefore, in the present work, the processes like conventional diamond grinding, electric discharge machining (EDM), and electric discharge grinding (EDG) are compared on the basis of material removal rate (MRR) and surface finish (Ra). EDG is the hybrid process of EDM and grinding and hence utilizes the benefits of both processes to give better MRR and surface finish than the parent processes. The MRR achieved in the EDG process is up to 50 times higher, and the surface roughness is at least 4 times better than the EDM process. The surface finish obtained by the EDG process is at least 4.5 times better than the conventional diamond grinding process and 3 times lower than cryogenically cooled conventional diamond grinding process. Surface and subsurface cracks, pit formation, and micropores were observed after conventional diamond grinding and EDM, but no such drawbacks were found on the selection of proper process parameters in case of the EDG process. Hence, surface finish and MRR obtained in EDG are better than EDM and the conventional diamond grinding process.