Abstract
We apply magnetomechanical effect of ferromagnetic Co binder to investigate distributions of plastic strain in cemented carbide tools under turning. By turning without magnetic field, pre-magnetized WC-Co inserts showed demagnetization at plastic deformed area. In opposition, by turning under magnetic field, pre-demagnetized inserts showed magnetization at almost the same area with certain differences. The change of residual magnetization increased with the cutting force and cutting length, and showed saturation afterwards. These magnetic changes are explained from a magnetomechanical effect of the "law of approach" from hysteresis to anhysteresis curve under the plastic deformation, which makes magnetic domain walls unpinned from dislocations. Under no influence from the external magnetic field, demagnetization distribution will well predict area of plastic strain in machining tools.
