Modelling of the friction in the CHIP formation zone depending on the rake face topography

Abstract In the machining process, both the tool wear and the surface integrity of the machined workpiece are significantly influenced by the friction. For this reason, the reliable prediction of friction behavior is of great importance for simulation-based tool and process design. It is known from previous investigations that the relative speed is a significant factor influencing the friction behavior between metallic materials and cemented carbide. The exact relationship, particularly in relation to the topography of the tool surfaces, is mainly unexplored. In the context of this publication, results from a friction characterization under machining-similar conditions for AISI 1045 and differently prepared cemented carbide surfaces are presented. The focus of the paper is to develop models for the friction coefficient, based on these results, which take the relative speed and the surface topography into account. Within a Finite-Element chip formation simulation, these models are compared to conventional models that assume the friction coefficient to be constant. For the validation of the simulations, results are used, which were determined from orthogonal cutting tests with differently prepared rake faces. Within the scope of these cutting tests, knowledge was gained about the influence of the rake face topography and the cutting parameters on the friction in the secondary shear zone.