Temperature in Intermittent Cutting

Abstract

It is customary to assume that intermittent cutting temperature is much lower than steady-state temperature. However, according to the findings of experimental studies and the supporting theoretical calculations, the intermittent cutting temperature at the end of the cutting stroke (with a sufficiently long length) approximates to the temperature of steady-state cutting. This is due to a higher rate of plastic deformation in the chip formation zone and in the contact zone during intermittent cutting and, as a result, due to a higher intensity of heat output. It has been established that the cause of a higher plastic strain rate is a smaller amount of chip shrinkage and, as a consequence, a higher rate of its movement along the front face of the tool. The simplest, most accessible method for estimating temperatures, which provides for higher accuracy of calculations, is the calculation method by A. N. Reznikov. This technique is based on the most common thermo-physical method of solving the differential equation of thermal conductivity—the method of heat sources—in accordance with which the layout of sources and heat sinks during steady-state and intermittent cutting are adopted. To verify the results of the calculation, the cutting temperature was determined by a well-known and widely used method—the method of a natural thermocouple.