Physical modelling with experimental validation of high ductility metal cutting chip formation illustrated by copper machining

摘要: This paper addresses problems of predicting chip formation in high strain machining conditions. A complete physical model of chip formation requires both plasticity and chip/tool friction models. Friction models are commonly partly phenomenological, with friction coefficients measured from the conditions in which the models are applied. This paper's thesis is that friction emerges from the plastic response of the chip material in contact with the cutting tool. Extremely large strains are generated in the contact region. In the case of machining highly ductile metals large strains also occur in the bulk of the chip. This paper applies a Mechanical Threshold Stress plasticity model extended to high strains (equivalent strains >5) to simulating chip formation in copper machining, without assuming measured values of friction coefficients. In the case of copper machining there is not a unified source of experimental knowledge …