Wire-EDM: a potential manufacturing process for gamma titanium aluminides in future aero engines

Abstract

Intermetallic TiAl-based alloys represent an important class of lightweight and high-temperature structural materials, ideal for future aircraft engines, with a potential to replace the extensively used nickel-based superalloy Inconel 718. However, due to their improved strength, the manufacturing of components from conventional machining processes is nearly impossible and results in high tool wear. Recent advancements in wire electric-discharge-machining (wire-EDM) technology have made the process capable of cutting hard materials with accuracy, confirming to tight quality standards, meeting huge production targets, in a flexible and an inexpensive manner. In Germany, recent research on wire-EDM of Inconel 718 has shown negligible white layer and an acceptable fatigue performance, in producing the fir tree slots in jet engines. This paper reviews the feasibility of wire-EDM as the preferred machining process over traditional broaching process, for gamma titanium aluminides in future jet engine components.