Heat flux in cutting: Importance, simulation and validation

The trends of machining difficult-to-machine materials and of dry machining or MQL lead to high temperatures in the cutting zone and increase the importance of thermal factors in the machining process. Besides amplified thermal tool loading and wear, the thermal fluxes affect the machining accuracy due to thermo-elastic deformations. Thus it is extremely important to know the magnitudes of these heat flows in order to assess the machining process heat and the tool wear and to develop compensation strategies against thermal tool center point (TCP) displacements. Based on the FE modeling of the cutting processes, the paper describes methods of determining the generated thermal energy and heat fluxes. Furthermore, new methods are presented how and in which partitions this heat flows into the workpiece, the tool and the chips. In order to validate the methods, 2D FE models are compared with temperature and force measurements carried out on a broaching test bed. The methods are applied on cutting examples which are investigated in the papers of Komanduri and Hou using analytical models. Thus, the simulation allows an assessment of the heat fluxes in real cutting processes in comparison with analytical and simplified numerical models.