Analysis of Tool Wear Rate during a Rotation of Cutter in Fly Cutting

Tool life is recognized as a critical factor in finishing a fine surface as well as high machining accuracy in cutting operation. The tool wear progress, therefore, should be evaluated in cutting simulation before the operation. This paper presents an analysis of tool wear rate during a rotation of tool in fly cutting as a manner of gear machining. The distribution of tool wear rate is analyzed with the stress and the temperature on the rake face based on a tool wear characteristic equation. The cutting force is estimated in a chip flow model, which piles up the orthogonal cuttings in the plane containing the cutting and the chip flow directions. The chip flow direction is determined to minimize the cutting energy. Then, the cutting temperature is analyzed numerically in the finite volume method, where the mechanical energy is converted to the heat generation in the shear zone and the rake face. In the fly cutting, the stress and temperature change with the uncut chip thickness and the tool-chip contact area during a rotation. Therefore, the instantaneous tool wear rates are analyzed for the rotation angles by the stress and the temperature distributions. This paper demonstrates an example of the tool wear analysis in cutting processes of a carbon steel. A cutting test was conducted to identify the force model with the orthogonal cutting data used in the analysis. Then, the temperature and tool wear distributions on the rake face are analyzed with the uncut chip thicknesses and the tool-chip contact areas.