A Microplasticity Analysis of Micro-Cutting Force Variation in Ultra-Precision Diamond Turning

This paper describes a microplasticity model for analyzing the variation of cutting force in ultra-precision diamond turning. The model takes into account the effect of material anisotropy due to the changing crystallographic orientation of workpieces being cut. A spectrum analysis technique is deployed to extract the features of the cutting force patterns. The model has been verified through a series of cutting experiments conducted on aluminum single crystals with different crystallographic cutting planes. The results indicate that the model can predict well the patterns of the cutting force variation. It is also found that there exists a fundamental cyclic frequency of variation of cutting force per revolution of the workpiece. Such a frequency is shown to be closely related to the crystallographic orientation of the materials being cut. The successful development of the microplasticity model provides a quantitative means for explaining periodic fluctuation of micro-cutting force in diamond turning of crystalline materials.