Papers by Author: Toshimichi Moriwaki

Abstract: In order to pursue possibility to machine sintered Tungsten Carbide by milling, series of ball end milling experiments are carried out with use of ball end mills made of sintered PCD and sintered CBN to machine flat inclined surface of sintered Tungsten Carbide. The experimental results show that the sintered Tungsten Carbide can well be machined by end milling. The ball end milling is also applied to finish rounding of the edges of the gear teeth. The maximum surface roughness of the finished gear teeth obtained is 1.1μm.

Abstract: Tungsten Carbide have extremely high hardness and wear-resistivity compared with conventional steel materials, and it is expected that the Tungsten carbide can be applied widely to dies and molds in the near future. In order to develop an efficient machining method of Tungsten Carbide for the dies and molds, series of cutting experiments were carried out to turn the sintered Tungsten Carbide materials with CBN tool. The selected sintered Tungsten Carbide workpieces are those containing Tungsten Carbide grains with mean grain size of 5μm, and 15wt%, 20wt% and 22wt% of Cobalt binder. The sintered CBN tool selected contains super-fine grains of CBN with mean grain size of 1μm. The cutting speed was varied from 10m/min to 60m/min, and the tool wear and the surface roughness were measured. It is concluded that the tool wear is less when cutting the sintered Tungsten Carbide containing larger amount of Cobalt binder. The surface roughness of about 2μm in Rz is obtained.

Abstract: A new ultrasonic vibration cutting device for ultraprecision elliptical vibration cutting has been developed. The elliptical vibration cutting device developed utilizes combination of bending and longitudinal modes of vibration of the stepped vibrator to generate circular or elliptical vibration locus at the cutting tool edge. The design principle as well as the structure and the performance of the elliptical vibration cutting device is introduced here. The experimental results of diamond cutting of Co-Cr-Mo Alloy proved that good surface quality with roughness of 20 nmPV can be obtained stably with the elliptical vibration cutting device developed.

Abstract: In this paper, turning with actively driven rotary tool was investigated. The influence of machining conditions such as tool rotational speed and inclination angle on the cutting edge temperature is examined experimentally. The temperature was measured by a thermocouple of constantan wire and work material. Experimental results show that the cutting temperature decreases with increasing tool rotational speed to a minimum value at a certain tool rotational speed and then increase. Next, the minimum temperature recorded by tool rotation was approximately 150oC lower than that the cutting with a non-rotating tool. Finally, the cutting temperature also decreases with the increase of inclination angle to a minimum value at an inclination angle.