Size Dependence Of Specific Energy Research Articles

Mechanics of mixed-mode ductile material removal with a conical tool and the size dependence of the specific energy

The mechanics of material removal during a single-grit rotating scratch has been investigated both analytically and experimentally. The models for cutting, plowing and mixed modes of material removal are analyzed based on the pressure and the frictional resistance. The mixed-mode model takes into account the contribution of built-up edge (BUE) ahead of the tool. To validate the model, single-grit rotating scratch experiments were conducted with a conical diamond tool on pure titanium. It was noticed that the adhesion between the tool and the deformed material, and the hardening properties of material play active roles in the scratching process and provide a driving force to the formation of the BUE. The overall frictional coefficient was found to oscillate strongly on both ends of the scratch but increases steadily over the central span of the scratch length. It is shown that the mixed-mode model captures the salient features of material removal and the size dependence of specific energy during the formation of a rotating scratch. The size dependence of specific energy may be attributed to the size effect of the yield pressure in titanium.