Characteristic analysis of EDMed surfaces using the Taguchi approach

The electro-discharge machining (EDM) process plays an important role in manufacturing tools and dies. However, the performance and service life of an EDMed workpiece is greatly influenced by the surface characteristics developed during surface erosion. In this research, the Taguchi method was employed to evaluate the main factors influencing the characteristics of EDMed surface. With an aim to minimizing the formation of defects and obtaining optimum working conditions of EDM. Analyzed results show that the main influencing factors for hole-enlargement are pulse current, pulse-on duration, and gap voltage. The main influencing factors for surface roughness are the pulse current, pulse-on duration, and specimen materials, while gap voltage is found to have only a negligible effect. Pulse current and pulse-on duration are the most important influencing factors affecting the thickness of the white layer. Estimations and confirmation experiments were performed, verifying the Taguchi predictions.