Coupled thermo-mechanical sticking-sliding friction model along tool-chip interface in diamond cutting of copper

Dynamic evolution of cutting temperature in the ongoing ultra-precision diamond cutting process with ultra-small material removal depth possesses a strong impact on the tool-chip friction states. In the present work, we propose an improved sticking-sliding friction model for diamond cutting of copper with the consideration of coupling thermo-mechanical dynamic evolution of frictional stress at tool-chip interface. Specifically, analytical investigation is performed to derive the correlation of activation conditions of sticking and sliding friction states with not only the evolution of coupled thermal-mechanical friction stress at tool-chip interface, but also the evolution of cutting temperature caused by tool-chip gap-induced heat loss. Subsequently, the effectiveness of improved sticking-sliding friction model is evaluated by finite element simulations and corresponding cutting experiments incorporated with high speed camera monitoring. Furthermore, the effects of depth of cut and rake angle of cutting tool on the tool-chip friction states in diamond cutting of copper are evaluated. Current findings provide insights for understanding and tailoring the tool-chip friction in small-scale metal cutting.