Evaluation of the Machinability of Nickel-based Superalloy with Coated Carbide Cutting Tools

Abstract

Nickel-based superalloys Inconel 718 and Mar-M247 have been widely employed in modern manufacturing owing to their good strength to weight ratio and excellent corrosion resistance. However, little literature is available dealing with the milling process in Mar-M247. Moreover, from published literature on milling of the two materials, it is difficult to directly apply the research findings from one material to the other to select the most appropriate tool coating and cutting conditions due to the different machining set-up. A comparative experimental study was conducted in this paper, using the same machining set-up to investigate the performance of cemented carbide coated inserts in milling difficult-to-machine materials. Performance of the coated cutting tools-TiN coated, TiCN coated and TiAlN coated-were compared with respect to tool failure mode, tool life, surface integrity of the workpiece, and chip segmentation. The effects of cutting speed, feed rate, and depth of cut on the tool life and surface roughness were also studied experimentally. Based on experimental data, the similarities and differences between Inconel 718 and Mar-M247 were quantitatively compared and explained, in which helps to evaluate the separated machining properties even though both materials belong to the same Nickel-based superalloy family.