Finite element modeling of the broaching process

This paper assesses the suitability of the finite element method for predicting the machining forces which occur during the broaching process. Results from finite element predictions are compared with experimental results obtained while broaching slots into Inconel 718 and Titanium Alloy specimens. Dry cutting conditions were investigated in the experiments because these were the conditions used for simulations. In the experiments, the cutting and perpendicular forces were measured for a range of cutting depths and tool rake angles. In the finite element simulations, the same two cutting variables, i.e. the tool rake angle and the cutting depth, were systematically changed, while keeping the other variables unchanged, in order to obtain a general understanding of the effects of these two cutting variables on the broaching behavior of Inconel 718 and the Titanium Alloy. The comparison shows that the finite element method can provide reasonably accurate predictions for the cutting forces, for the two materials. However, although the general trends in the variations of the perpendicular forces with the rake angle and cutting depth can be reasonably predicted, for the two materials, the absolute perpendicular forces are not as accurately predicted as the cutting forces. The results provide a useful guide to the choice of the most effective tool design and methods to optimize the cutting variables in order to achieve acceptable machining costs.