A Predictive Model for Thin Plate Deformation in Surface Milling

摘要

Micro-fabrication of complex parts often relies on milling processes in meeting its dimensional and surface finish requirements. However, machining process generally induces residual stress on the part surface due to complex thermo-mechanical coupling effect in and near the metal removal zone. In this study, a predictive model for the deformation of thin plate down to 0.6 mm machined by an end mill is established. The effective force due to residual stress for the same milling conditions is assumed to be the same irrespective of the plate thickness. The depths of effective residual stress for a range of milling parameters are found from a series of experiments via the effective moment assumption. The deformation model is further simplified by adapting the average value of these residual stress depths as a constant depth. The final predictive model requires only a deformation measurement at a certain thickness to predict deformation at a different plate thickness under the same set of cutting conditions. The validation experiments show that the presented predictive model yields maximum error of about ten percent compared with measurements for a wide range of milling conditions with different milling type and cooling condition.