In Inconel718 cutting with a cubic boron nitride (CBN) tool, notch wear caused by extruded built-up edge (BUE) along the cutting edge and secondary chip due to a side flow occurs significantly outside of the depth-of-cut line. The BUE extrusion behavior depends on tool geometry, such as chamfer angle, chamfer width and rake angle. The secondary chip easily forms if curled BUE is extruded unstably. On the other hand, the stable uncurled BUE extrusion causes neither the secondary chip formation nor the notch wear. In this study, the optimization of tool geometry for obtaining the stable BUE extrusion is attempted to suppress the notch wear.
