Investigations of tool geometry in ultraprecision cutting: A FEM simulation approach

Based on Lagrange formulation, JC material model and criteriain of Cockroft-Latham, FEM model of ultraprecision cutting is presented. In this study, considerations in the tool edge radius, FEM model of cutting is presented to simulate the chip deformation, cutting force and stress-effective distribution in order to consider the interactive influences of tool edge radius, rake angle and clearance angle on cutting process. The effect of tool geometry on cutting process is analyzed. Results show that chip can create lateral flow and the length of contacted chip-tool increases with the rake angle reduced; the rake angle and clearance angle is suitable bigger, cutting force and stress-effective of cutting surface decrease correspondingly. The effect of tool edge radius on extrusion and friction of cutting surface is related to the degree of sharpness of tool, the tool edge radius is bigger, cutting force and stress-effective of cutting surface increase correspondingly. The maximal stress-effective distribution is around cutting lip. The distribution region of maximal stress-effective can cause tool wear such as crater. The tool geometry should be selected reasonably according to the analysis.