Die-sinking of super dielectric based electrical discharge machining using 3D printed electrodes

Abstract

Electrical discharge machining (EDM) is a popular nonconventional manufacturing process for the machining of complex or hard materials that are difficult to machine by the conventional machining process. In the EDM process, the electric current is used to ablate the material, and there is no contact between the tool and workpiece. One of the variants of the EDM process is the die sinking EDM where the electrode shape is mirrored in the workpiece, and die sinking electrodes are usually manufactured using conventional machining process. However, in the die sinking EDM process, the material removal rate is significantly lower than the conventional machining. Due to this fact, the regular die sinking EDM process is unable to meet the demands of today’s fast moving manufacturing industry. This study presents an innovative electrode design strategy together with a super dielectric machining fluid to tackle the low-efficiency issue of the die sinking EDM process. In general, flushing becomes very important when deep features are machined. In the die sinking EDM process flushing holes in the tool electrode is considered impractical, and the regular method of flushing is not effective because of the accumulation of a large amount of debris in the machining zone. In this study, 3D printed die sinking EDM electrode with multiple through electrode flushing channel for high-pressure flushing is introduced. In addition, an innovative super dielectric based EDM fluid is proposed in this study, which provides high capacitive plasma in the machining process and ensures better machining efficiency. The effect of super dielectric fluid on the EDM plasma has been analysed and compared with the plasma physics theory. The performance of the proposed 3D printed multi flushing channel electrode together with super dielectric fluid for the feature manufacturing has been demonstrated by making multiple features efficiently in hard to cut materials.