Abstract: The optimization of parameter values in electrical discharge machining(EDM) has become one of the big problems in non-traditional manufacturing field especially the optimization of EDM parameter values with multiple performance characteristics due to the reason that the knowledge of EDM mechanism acquired has still been much limited until now. On such an occasion, a new theory or method ought to be created or utilized from the interdisciplinary approaches. The grey relational grade theory,therefore, is employed to optimize the parameter values with multiple performance characteristics on the basis of the experimental results with orthogonal array The paper also makes a detailed analysis of the effects of different electrical parameter values and non-electrical parameter values on such performance characteristics as machining speed, electrode consumption and hole clearance. As a result, the ptimized parameter values are obtained through the simplified procedure by applying grey relational grade into the optimization of parameter values with multiple performance characteristics.

Key words: Electronic discharge machining, Grey relational grade Orthogonal array, Micro electronic discharge machining