Characterization of friction behavior under cryogenic conditions: Ti-6Al-4V

Friction phenomena at the chip/tool/workpiece interfaces during machining of material impacts significantly the cutting process. In this article, the effect of friction conditions (dry, emulsion, cryogenic) on the tribological performance of uncoated tungsten carbide tools is investigated when machining titanium alloy Ti-6Al-4V. Friction tests were conducted to analyze the impact of sliding speed and cooling on the evolution of the friction coefficient. To determine the real friction coefficient (adhesive friction coefficient), a numerical simulation using the Lagrangian method was employed. After a comparative study of various simulation methods ("Lagrangian", "CEL", and "ALE"), the Lagrangian method was identified as the most relevant. The obtained results reveal that an increase of sliding velocity significantly influences the friction coefficient. Additionally, the application of cryogenic fluid (LN2) reduces the friction coefficient compared to both dry and emulsion -based friction. Adhesion phenomena play a crucial role in the nature of the contact, especially at high sliding velocities.