An Analysis of the Mechanism of Orthogonal Cutting

Abstract

The orthogonal cutting mechanism with the transitional deformation range (i. e. the "flow region" which exists between the rigid region of workpiece and the plastic region of steady chip), instead of the conventional shear plane, is analyzed theoretically in the case in which simple continuous chip is produced under the assumption of a perfectly plastic solid. Using the results, the experimental data for lead and brass are discussed. In all cases the starting boundary-line of flow region is situated under the conventional shear line, and the ending boundary-line above it. The inclination angles of both boundary-lines and the sector angle of flow region increase with rake angle. With an increase of depth of cut, the inclination angle of starting boundary-line increases, while that of ending boundary-line and, hence, the sector angle increase in the case of lead, but decrease in the case of brass. Furthermore, the strain of chip decreases with an increase of rake angle, and it has a tendency to decrease slightly in the case of lead and increase gradually in the case of brass with an increase of depth of cut.