Finite element modeling of friction at the tool-chip-workpiece interface in high speed machining of Ti6Al4V

For achieving the accurate FE modeling of friction, a new analytical formula of the friction coefficient at tool-chip-workpiece interface is first derived, which takes into account the actual cutting tool's blunt radius rather than conventionally simplified sharp edge. And the mean friction coefficient mu(m) applied to the FE model in HSM of Ti6Al4V is obtained by using three-method combination of the new analytical formula and the FE simulation as well as the experimental verification of outside-diameter grooving with uncoated carbide tool. The results show that mu(m) is between 0.4 and 0.5 in the grooving speed range from 49.4 m/min to 122.5 m/min. The validity of mu(m) in value is further verified by the agreement of the simulated chip shapes with the experimentally measured SEM morphologies.