Influence of lubricant penetration on cutting forces, tool wear, and chip morphology in machining Inconel 625 across different machining environments

The effectiveness of MQL on the machining of Inconel alloy for varied depths of cut (DC) - 1.00, 1.25, and 1.5 mm is investigated. As the cutting depth increases, the process forces under wet (flood) conditions exhibit a greater increase compared to MQL due to the reduced effectiveness of coolant penetration into the cutting zone as the DC rises. In MQL, the cutting force is approximately 14% lower compared to wet for the highest DC of 1.5 mm. For all DC levels used in this investigation, MQL possessed lower friction coefficients than dry and wet machining as a result of enhanced aerosol penetration and thin-oil layer formation in the chip-tool interface. In MQL, the crater wear is also reduced, owing to decreased tool-chip contact and improved lubrication effects. The investigation of shear angle and chip segmentation height also reveals that the lubrication effect is enhanced under MQL.