Temperature fields in a chip during high-speed orthogonal cutting - An experimental investigation

During the cutting process, the temperature field in the chip is measured by using the principle of pyrometry in the visible spectral range. The mechanical device developed to reproduce orthogonal cutting conditions and to reach very high cutting speed (up to 120 m/s) is used for a range of velocities from 10 to 70 m/s. The presented experimental results concern two materials chosen following the form of chip generated: a low carbon steel (C 15) and a low alloyed medium carbon steel (42CrMo4). The performances of the measurement setup are completed by the possibility of recording real time photographs of the chip formation. These records make the analysis of temperature maps easier and allow specific parameters as the contact length at the tool-chip interface or the shear angle to be determined. The non-uniform heating in the chip is emphasized by the presence of a maximal temperature area. The temperature fields measured for a cutting speed around 20m/s present maximums of 870 degrees C for 42CrMo4 and 630 degrees C for C15 located near the tool-chip interface. The effects of cutting velocity on the maximum temperature value in the chip and the location of this heat zone are presented. This maximum increases with the cutting velocity contrary to its location which presents few variations. The experimental results are compared with an analytical approach. (C) 2006 Elsevier Ltd. All rights reserved.