Investigation of the local friction behavior in the secondary shear zone by coupling of chip formation and microscale contact simulation

This study examines local friction behavior at the chip–tool interface in metal cutting by integrating chip formation and microscale contact simulations. This research examines the mechanical effects of high-pressure metalworking fluid (MWF) supply on chip formation, specifically its impact on frictional interactions at the tool–chip interface. Through finite element modeling and a microscale contact model, this study provides detailed insights into the effects of high-pressure MWFs on local friction coefficients, contact length, and pressure distribution in the secondary shear zone. Experimental validation using high-speed orthogonal cutting tests demonstrates strong agreement between simulated and observed results, confirming the effectiveness of the multi-scale model. The findings suggest that optimized high-pressure lubrication significantly enhances tool life, reduces process forces, and improves surface quality, making it a valuable strategy for advanced machining applications. • Developed a multi-scale simulation coupling chip formation with microscale contact. • Studied high-pressure cooling lubricants’ impact on secondary shear zone friction. • Demonstrated significant friction reduction and tool–chip contact length decrease. • Validated simulation results with high-speed cutting experiments. • Proposed future enhancements integrating thermal effects and coolant formulations.