Electrode wear estimation model for EDM drilling

Electric discharge machining (EDM) is commonly used to machine precise and tiny parts when conventional cutting methods face difficulty in meeting productivity and tolerance requirements. Especially, EDM-drilling is an efficient process for the fabrication of micro-diameter deep hole even though material type is difficult to cut such as high strength steel, cemented carbide, and titanium alloys. EDM drilling is excellent for machining deep and narrow holes regardless of material hardness and location, whereas die-sinking EDM works well to machine micro-parts and perpendicular walls of die and molds. However, the electrode wear of EDM-drilling is rapid compared to that of die-sinking EDM and makes it difficult to control the electrode feed and machine precisely. Thus, this paper presents an effective model to estimate the electrode wear of EDM-drilling. To validate the proposed method, a commercial EDM drilling machine was used. Experimental results show that electrode wear amount can be predicted acceptably.