An Analysis of the Mechanism of Discontinuous Chip Formation

Abstract

The mechanism of formation of discontinuous chip in metal cutting was analyzed theoretically with the concept of regional plastic flow in the flow region instead of the conventional concept of single slip along the so-called shear plane. The relationship between formations of continuous and discontinuous chips was reasonably explained. Theoretical expressions for inclination angles of the ending boundary line of the flow region, i.e., fracture surface, the starting boundary line of the flow region, and the shearing strain in the discontinuous chip fragment were deduced and ascertained to be in agreement with the experimental results for carbon steel. Moreover, the shearing stress-strain diagram in metal cutting was discussed and compared with that in static material tests.