Evaluation of adhesion on tool-chip interface with dynamic components of cutting force

A new method for evaluation of adhesion in cutting is proposed. Adhesion of chip induces fluctuation in chip flow or stick-slip movement of chip, so that dynamic component of cutting forces depends on the cutting conditions and properties of the work materials. Continuous turning of a medium carbon steel, a titanium alloy and a nickel-based super heat resistant alloy were carried out. Dynamic components of cutting force were measured by piezoelectric dynamometer. In cutting of a medium carbon steel, the dynamic components below 500Hz increased under the condition of build-up edge (BUE) formation, and gradually decreased with increase of cutting speed. Deposits of work piece on tool face were also observed under conditions in which the power spectrum of cutting force showed peaks. Authors defined friction-coefficient vector on rake face of cutting tool. Fluctuation in the friction-coefficient vector was calculated as for a range of cutting speeds under dry condition and emulsion supply in order to investigate the relationship between adhesion and fluctuation of the dynamic components. Tendency to adhesion was evaluated with newly defined index among a carbon steel S45C, a titanium alloy Ti-6A1-4V and a nickel-based super heat resistant alloy Inconel718, yielded good agreement with empirical rules.