FEM-Modelling of the Thermal Workpiece Deformation in Dry Turning☆

Abstract The substitution of wet machining processes by dry processes is an important development in manufacturing technology. A central challenge is the significant higher heating and thus the resulting thermal expansion of the workpiece which leads to geometrical deviations of the machined part. According to the state of the art these processes are optimized by trial and error approaches and therefore result in high costs. This paper presents a two-scale finite element model which calculates the thermal deformation of the workpiece in dry turning of normalized steel C45E / AISI 1045. The approach consists of two submodels. The first submodel is a fully coupled finite element chip formation model for the calculation of the generated heat and temperature distribution in the chip, workpiece and tool. On this basis the rate of heat flow into the workpiece is determined. In a second model this rate of heat flow is applied to a macroscale model that calculates the instationary temperature distribution and deformation of the whole workpiece. The chip formation model has been validated by an orthogonal cutting process realized on a broaching machine tool while the workpiece model is validated by thermal imaging of an orthogonal turning process.