Development of an energy consumption map for turning inconel 718 through coupled chip-morphology and...

Sustainable machining of Inconel 718, a nickel-based superalloy that is highly valuable in aerospace, is faced with the challenge that it has high energy requirements and poor machinability. In this study, a new energy consumption map and combined energy-morphology framework is proposed which draws a correlation between a specific cutting energy (SCE) and the mechanics of chip formation. Detailed experimental profiling maintained over a variety of cutting speeds (25-75 m/min ) and feed rates (0.05-0.20 mm/rev) demonstrates a SCE profile with a high-energy ridge of greater than 3.0 J/mm³ at lower feed rates, and a low-energy trough of less than 2.0 J/mm³ at higher speeds and feeds. Quantitative measurements of chip morphology suggest that low-SCE conditions are coupled with fine serrations, shear bands of less than 24 μm, compression ratios of less than 1.2, and relatively large included angles hence indicating efficient thermally assisted shear localization. The best processing window of 62.5-75 m/min and 0.10-0.15 mm/rev was found that allows to save energy and at the same time improve chip control. The derived energy-morphology map is a viable tool of shop-floor decision making, which helps to achieve energy-efficient machining.