A general cutting process model for high-speed machining: Dynamic and thermal considerations

The objective of this work is to develop a general cutting process model for high-speed machining (HSM) that can predict the optimum cutting conditions which result in high productivity rates, small workpiece surface error, and reasonable machine-tool life.; The general cutting process model is developed as a closed loop interaction between two component models, namely a mechanistic dynamic model and an analytic thermal model. The dynamic model uses the finite element method and the associated modal analysis technique in order to predict the vibration of the tool-work system for different machining conditions. When predicting the vibration of the tool-work system, the dynamic model investigates two types of machining, namely constant speed machining (CSM) and variable speed machining (VSM). The thermal model solves analytically three coupled heat conduction problems inside the chip formation zone, tool, and workpiece in order to first predict how the heat generated during the cut is partitioned among the tool, chip, and workpiece and then predict the cutting temperatures.; The mechanistic dynamic model was used to predict the optimum cutting conditions for tool-work systems having one or multiple coupled modes of vibration remaining unchanged or changing throughout the cut. The model indicated that for tool-work systems having simple geometries and hence dynamics, CSM can be used to achieve high productivity rates and a good surface error. However, for tool-work systems with complex geometries and dynamics, the model suggested that variable spindle speed machining is safer to use than CSM when trying to obtain high productivity rates. The validation work indicated that the dynamic model predicts well the vibration of the tool-work system during HSM.; The analytical thermal model was used to investigate the tool-chip interface temperatures developed during the cut. The thermal model indicated that, for all tool and workpiece materials investigated and for both continuous and interrupted cutting, the tool temperature and hence the tool wear increase with speed. To verify the analytic thermal model, the predicted temperatures were compared with data published in the literature for different cutting processes, tool-work materials, and machining conditions. The validation work indicated that the thermal model predicts well the tool-work temperatures fields. (Abstract shortened by UMI.)...