Cutting force prediction performance of a microcutting slip-line field model in brass machining

Among models describing the machining process taking into account a rounded-edge tool, the slip-line field model developed by Waldorf [5-6] for the macroscale allows to separately evaluate shearing and ploughing force components in orthogonal cutting conditions, therefore it is suitable to predict cutting forces when a large ploughing action occurs, as in micromachining. The present work aims at objectively verifying the cutting and feed force prediction performance of the Waldorf model within typical microscale cutting conditions (uncut chip thickness lower than 50 µm and comparable in size to cutting edge radius) in its original version and in a modified version considering the effective rake angle. In order to do that, the present work relies on a clear and repeatable procedure for the model calibration and application which has been developed and presented in a past work of the same authors [28]. The models performance comparison have been carried out with tests on C38500 brass (CuZn39Pb3) alloy at different cutting speeds and different ratios between uncut chip thickness and cutting edge radius.