Evaluation of tool wear, energy consumption, and surface roughness during turning of inconel 718 using sustainable machining technique

Abstract

Heat resistant alloys such as Inconel 718 present challenges to manufacturing industries during its machining. Machinability of such alloys can be improved using smart cutting conditions. Further, to seek improvements in the machinability of Inconel 718, this assessment evaluates industry-relevant machinability indicator, i.e., tool wear in terms of both flank and crater wear under indigenously developed cryogenic turning technique and compares the results with conventional dry and wet turning techniques. Experimental results show a massive improvement (133%) in tool life under cryogenic turning as compared with the dry turning. However, tool life obtained under wet and cryogenic turning is comparable. In the second part of this paper, industry-relevant machinability indicators namely energy consumption, chip reduction coefficient (CRC), and average surface roughness (Ra) were critically examined at different material removal rates (MRR) for turning of Inconel 718 under different cutting environments. A total 24 number of experiments were designed using full factorial considering two levels of cutting speed (vc) i.e., 45 and 60 m/min, four levels of feed (fr) i.e., 0.03, 0.06, 0.12, and 0.24 mm/rev, and three cutting conditions (dry, wet, and cryogenic). The results show that energy consumption in cryogenic turning reduced up to 8–17% when compared with dry and wet turning. Ra values for cryogenic turning also reduced up to 20–37% in comparison to dry and wet turning at various MRR. Improved tool life, reduced energy consumption, and Ra values obtained under cryogenic turning echo its potential to replace unsustainable conventional machining practices.