Modeling of cutting force in MQL machining environment considering chip tool contact friction

The present study deals with the prediction of machining forces under minimum quantity lubrication (MQL) environment by considering the contact length and chip thickness. The proposed methodology is an extension of Oxley's predictive machining theory (OPMT) to MQL machining. A novel approach to modify OPMT model has been used to incorporate the effects of lubrication at the chip-tool interface. Dual contact zone theory (sticking sliding) has been used to model the frictional force in MQL machining. A mechanistic model for the local coefficient of friction (COF) has been developed as a function of cutting conditions and MQL parameters. The proposed model predicts cutting forces, contact length and chip thickness under MQL environment with reasonable accuracy and the same has been validated by experimental work.