Implementing Sustainable Cryo-MQL Grinding Practices for Improvement of Tribological Characterizes of Inconel 625

Abstract Cryo-MQL is an impactful, sustainable cooling/lubrication approach that addresses constraints such as wheel loading and thermal damage of ground Inconel 625 caused by its low thermal conductivity and work hardening tendency. The present investigation explores the eco-friendly Cryo-MQL approach, i.e., liquid nitrogen (LN2) with groundnut oil-based sustainable grinding, to enhance the grindability and surface integrity of Inconel 625. For confirmation, cryo-MQL outcomes, including grinding forces, roughness parameters, bearing area analysis, grinding temperature, surface morphology, and microhardness, have been compared with dry and MQL outcomes. The results indicate that cryo-MQL exhibits excellent surface tribological performance in lower skewness and kurtosis parameters with a higher bearing area ratio, i.e., 78.84%, and free-from grinding burn and redeposition layer formation. Besides, lower grinding forces and temperature with no significant microhardness change highlighted a better grindability of high-strength alloy. Finally, chip morphology investigations under various conditions have been performed to gain further insights into the grindability of Inconel 625 in terms of negligible wear tracks with long C-type microchips. Therefore, it can be concluded that cryo-MQL grinding safeguards the surface qualities of the ground surfaces and provides clean grinding conditions.