Enhancing Electric Discharge Machining Performance by Selecting Electrode Design and Geometrical Parameters for Square, Triangular, and Hexagonal Profiled Holes

Abstract

Manufacturing of dies, molds, and their allied components requires the machining of holes with different profiles. Electric discharge machining (EDM) die-sinking is a crucial process used in the dies and molds manufacturing industry. By nature, EDM die-sinking is a relatively slow process in terms of material removal rate (MRR) and there are high amounts of tool material loss in terms of tool wear rate (TWR) which directly influence dimensional accuracies and surface roughness (SR). Therefore, the process is continuously evolving to address these limitations. The present research is aligned in this direction such as to bring improvements in MRR, TWR, and SR through modifications to the conventional electrode design and its geometrical parameters. Traditional designs of EDM electrodes have a uniform cross-section through the tool’s entire length and have only one geometrical parameter, i.e., the tool’s cross-section. To improve the EDM performance, traditional designs are completely modified by introducing several geometrical parameters such as relief angles, land thickness, cross-sectional area, shank height, circular relief, and non-circular relief, etc. Electrode designs are employed to mill non-circular profiles including triangular, square, and hexagonal shaped holes. The EDM performance measures strongly depend on the tool’s geometrical parameters (design type, relief angle, land thickness), machining profile (circular, square, triangle, hexagon), as well as the height/depth of the machining feature. By selecting proper tool designs and corresponding geometrical parameters, the EDM performance measures can be improved significantly.