Effect of Orbital Tool Actuation during Electro Discharge Machining Process - A Critical Review

Electro Discharge Machining (EDM) is the most extensively used unconventional machining process in dies and molds industries. However, its capabilities are limited by high tooling cost and low material removal rate. Researchers have explored a number of ways to improve the performance of EDM process performance, one of the ways being orbital tool movement. The experimental and theoretical studies show that process performance can be improved considerably by tool orbiting along with proper selection of operating parameters. The orbital movement of tool electrode reduces the debris concentration at the discharge gap and thus reduces unstable machining and arcs. Tool orbiting allows standard sized electrodes to be used for a wide range of hole sizes and eliminates the need for custom made electrodes altogether. This paper contains the review of the research works carried out so far in the area of orbital EDM of different materials and shapes. It critically reports the available experimental and theoretical studies of orbital EDM to improve the process performance. In the final part of the paper, an outline is provided for trends in future research possibilities.