An Evaluation of Cutting Edge and Machinability of Inclined Planetary Motion Milling for Difficult-to-cut Materials

Recently, the applications of difficult-to-cut materials (e.g. CFRP and titanium alloy) are increasing in the aviation and automotive industries. Conventional drilling tools occur burr and/or delamination on their materials. The inclined planetary motion milling consists of two independent spindle motions which are tool rotation and revolution. Eccentricity of the tool rotation axis is realized by inclination of few degrees from revolution axis. The movement of eccentric mechanism can be reduced by comparison with that of the orbital drilling. The inclined planetary motion milling reduces inertial vibration and decreases cutting force. According to the geometrical cutting principle, it can be decreased delamination and burr of their materials, comparing to orbital drilling. In the study, the authors revaluated optimum cutting condition for titanium alloy by use of the experimental design and carried out its repeatability test. And the authors developed on measurement and evaluation method for cutting edge profiles and examined the comprehensive discussion of the relationship among change to cutting edge wear and surface texture and circularity on drilling hole, tool rotation torque after based on the practical drilling experiments.