Behaviors of end milling Inconel 718 superalloy by cemented carbide tools

End milling of Inconel 718 under various cutting speeds by cemented carbide tools was conducted. For slot milling, it is found that the increase of cutting temperature and strain hardening are responsible for the difficulty at low speed cutting. Tool failure is mainly in the form of chipping and breakage of the cutting edge. At medium cutting speeds, softening of work material due to special thermal stability property of γ′ precipitation of Inconel 718 leads to a reduction of cutting force, and tool life is improved with the increase of speed. But when cutting speed is further increased, most of the chips are welded on both sides of the slot, and chip flow is retarded. The cutting temperature would rise drastically and plastic deformation of cutting tool takes place eventually. Cutting speed plays a less important role in side milling since chips can flow more smoothly. Based on this study, it is found that high cutting temperature and difficult chip disposal are two main problems encountered in high-speed end milling of Inconel 718. It is also concluded that there exists an appropriate range of cutting speed in end milling of Inconel 718 by cemented carbide tools. On the contrary, feed does not have a significant effect for both kinds of milling operations.