Analytical Approach for Optimization of Chamfered Cutting Tool Preparation Considering Built-Up Edge Extrusion Behavior

A built-up edge (BUE) that is formed adjacent to a chamfered cutting edge is extruded along the cutting edge, if the appropriate chamfer geometry is selected. If a sharper BUE is stably extruded with high fluidity, notch wear at the depth-of-cut line and adhesion of the work material can be prevented. In this study, an analytical cutting model considering the BUE extrusion with a chamfered tool is proposed in order to optimize the chamfer preparation, i.e., chamfer angle and coefficient of friction between the chamfer face and the BUE, for the advantages of BUE extrusion. In this analysis, an empirical cutting model employing the slip-line field method and a BUE extrusion model using the slab method are coupled by static mechanics equilibrium. By coupling the two models, the shape of the BUE is uniquely determined. The calculated and experimental results in terms of actual rake angle and cutting force are roughly in agreement. The analytical results indicate that sharpness and the fluidity in the BUE extrusion can be simultaneously attained by preparing the tool with chamfer angle in which the material stagnation proceeds until the actual rake angle is equal to the rake angle of the tool.