Size effect in material removal by cutting at nano scale

The size effect in cutting process that the specific cutting energy increases rapidly and nonlinearly as the undeformed chip thickness (UCT) decrease is discussed. To facilitate the discussion, the specific cutting energy is analyzed by separating the cutting mechanism into two parts: shearing and extrusion. The size effect of materials such as dislocation starvation was introduced to explain the increase of specific cutting energy. In conventional cutting, shearing dominates the size effect. And as the UCT reduces, the effect of tool radius is not ignorable, and extrusion participates more in describing the size effect. When the UCT is on the nanometric scale, extrusion dominates the cutting process. Besides that, the cutting energy was further separated into surface generation energy, material disorder energy, and heat generation energy. Each of them was discussed individually. The results show that the size effect of materials plays a major role in the change of specific cutting energy. And the other aspects like surface generation and material disorder also determine the size effect in cutting process.