抄録
Sintered tungsten carbide is machined in ductile mode by applying “elliptical vibration cutting”, and the mechanics of the ductile mode cutting are investigated in the present research. Grooving experiments of the sintered tungsten carbide are carried out at low vibration frequency so that the vibration cutting process can be monitored easily. The groove machined by the elliptical vibration cutting is smooth without any visible fractures, while those machined by the conventional linear vibration cutting and the ordinary cutting are rough with numerous micro fractures. It is considered that the difference is caused by reduction of thickness of workpiece material cut in each cycle of the elliptical vibration. The same difference is confirmed at ultrasonic frequency, and it is also clarified that high quality surfaces are obtained when the vertical amplitude of the elliptical vibration is lower than 0.5 μm0-p, which corresponds to grain size of the sintered tungsten carbide. Based on these fundamental results, the ultrasonic elliptical vibration cutting is applied to ultraprecision planing of the sintered tungsten carbide, and ultraprecision machining with surface roughness of less than 50 nm Rz is realized, although the tool life is relatively short.
