Sustainability analysis of tool wear, energy efficiency, surface quality, and energy during dry, MQL, and wet turning of Inconel 718

Inconel 718 alloy is widely used in aerospace and industrial sectors due to its high durability under extreme temperatures and corrosive conditions. This study explores the effects of various cooling conditions and input parameters such as feed rate, cutting speed, and depth of cut on machining performance during turning of Inconel 718 using coated carbide tools. The aim is to enhance sustainable and productive manufacturing. Key machining responses like tool wear rate (R), surface roughness (Ra), specific cutting energy (SCE), and carbon emissions (CE) were evaluated using the 'smaller-the-better' criterion. Taguchi method and ANOVA were applied to identify the influence of each parameter and determine optimal settings. Tool wear was minimized at 25 mm/rev, 0.05 m/min, and 0.6 mm; Ra at 50 mm/rev, 0.05 m/min, and 0.4 mm under wet conditions. Under dry machining, optimal SCE and CE were achieved at 75 mm/rev, 0.05 m/min, and 0.4 mm, and at 75 mm/rev, 0.15 m/min, and 0.4 mm, respectively. Wet machining showed significant improvements in tool life and surface finish; dry machining yielded lowest SCE and CE. Multi-objective optimisation via TOPSIS ranked MQL as most balanced setup. Adhering to optimum conditions led to 23% reduction in tool wear, 15% in SCE, 8% in Ra, and 12% in CE.