Surface Roughness Performance of Cu Electrode on Hardened AISI 4140 Steels in EDM Process

Electrical Discharge Machining (EDM) is widely used unusual manufacturing methods due to the fact that requirement of cutting, brittle, hard and complex geometry. In this context, high-alloy and hardened steels used as mold material which is desired wearing resistance from the materials. The desired long-life criteria can also be achieved in many steel materials by cooling process. In this experimental study, surface roughness performance of Cu electrode in EDM process of hardened AISI 4140 steels was investigated. Discharge current, pulse duration, waiting period were determined as EDM processing parameters and two separate experiments were carried out on materials with different heat treatment processes. As a result of the experimental study, the surface roughness values were measured on machined workpiece surfaces and average surface roughness values were determined. It has been observed that the EDM processing parameters have variable effects on the surface roughness in heat treated workpieces. The results also show that EDM processing becomes more difficult and the surface quality decreases when AISI 4140 materials, which are cooled for a certain period of time, are subjected to tempering heat treatment. © 2022, Chinese Mechanical Engineering Society. All right reserved.