Application of CNC Electrical Discharge Turning for Aerospace Materials ? A Review

Electrical discharge machining (EDM) is considered as an efficient and economical machining tool in machining advanced alloys and composites in the present manufacturing industries. It is widely used non-traditional machining approach to generate complex contours on difficult-to-cut materials. The extensive capabilities such as precision, surface quality, ease of cutting distinct electrical conductive materials irrespective of their hardness, promoted this technique for numerous applications in the fields of aerospace, automobile, medical, die and mold production, precision tooling. During the past decades, a variety of EDM technologies were emerging to comply with the complexity of machined contour, metal removal rate, dimensional tolerances, surface integrity, etc. Among these, electrical discharge turning (EDT) is one of the applications of EDM technology developed to manufacture micro and macro axisymmetric cylindrical components such as miniaturized ejector pins in injection molds, components of micro air turbines and pumps, special needle points for human medicine, micro tools or microstamping dies. Turning by EDM has become an emerging area of research in the present and many experimental investigations were reported in the literature in view to improve its performance. In this article, the experimental and analytical investigation performed on the EDT to machine distinct metals, alloys, and composites during the past two decades is critically reviewed and presented its summary. This paper also presents a brief assessment of future research needs in the same area.