A Study on The Influence of Nd-Magnets On The Electrical Discharge Machining Surface Quality of Mild Steel

Abstract

Electrical discharge machining (EDM) is one of the processing methods based on non-traditional manufacturing procedures. It is gaining increased popularity, since it does not require cutting tools and allows machining of hard, brittle and intricate geometries. In recent years, EDM researchers have explored a number of ways to improve the surface state of work pieces machined using EDM. In the present paper, roughness value of work pieces machined under the influence of varied magnetic intensities, peak current and pulse durations is investigated. A new laboratory setup, incorporating Nd-magnets, is created to carry out the experiments together with a TOOLCRAFT A25 EDM. Empirical modeling has been carried out to establish a mathematical relationship between the roughness and the machining parameters. Optimum settings have been identified that produce lowest roughness values. Results indicated that the presence of a magnetic field in the spark gap region increases the surface roughness of the machined work piece. Surface roughness of work piece was also noted to be highly influenced by current and pulse on-time. Higher values of these parameters increased surface roughness. Low magnetic intensity, lower current, lower pulse-on time and relatively higher pulse pause time produced a better surface finish.

Keywords: Electric discharge machining (EDM); surface roughness.