In metal cutting processes, the use of cutting fluids shows significant effects on workpiece surface quality by reducing thermomechanical loads on cutting tool and workpiece. Many efforts are made to model these thermomechanical processes, however without considering detailed heat transfer between cutting fluid, tool, and workpiece. To account for heat transfer effects, a coupling approach is developed, which combines computational fluid dynamics (CFD) and finite element method (FEM) chip formation simulation. Prior to the simulation, experimental investigations in orthogonal cutting in dry and wet cutting conditions with two different workpiece materials (AISI 1045 and DA 718) are conducted. To measure the tool temperature in dry as well as in wet cutting conditions, a two color pyrometer is placed inside an electrical discharge machining (EDM) drilled cutting tool hole. Besides tool temperature, the cutting force is recorded during the experiments and later used to calculate heat source terms for the CFD simulation. After the experiments, FEM chip formation simulations are performed and provide the chip forms for the CFD mesh generation. In general, CFD simulation and experiment are in reasonable agreement, as for each workpiece setup the measured temperature data are located between the simulation results from the two different tool geometries. Furthermore, numerical and experimental results both show a decrease of tool temperature in wet cutting conditions, however revealing a more significant cooling effect in a AISI 1045 workpiece setup. The results suggest that the placement of drilling holes has a major influence on the local tool temperature distribution, as the drilling hole equals a thermal resistance and hence leads to elevated temperatures at the tool front.

In dry cutting an intensified heating of workpiece, tool and machine tool results in thermoelastic deformation which in turn causes dimensional and geometrical deviations of the machined parts. This paper presents a multiscale simulation method to calculate and compensate this effect. A chip formation model is used to compute the thermomechanical energy conversion and to determine the heat source of the cutting process on a mesoscopic model scale. This heat source is transferred on a macroscopic model that simulates the workpiece heating for a complete process sequence in order to analyze, reduce and compensate thermoelastic deformations. The multiscale simulation method is validated regarding the temperature and the resulting longitudinal workpiece deformation in dry turning of a gear shaft. However, the prediction of thermal deformation in radial dimensions needs additional validation with improved experiments and model features in future works