Several studies have indicated that ultrasonic vibration drilling improves cutting performance by reduction of cutting force, fragmentation of chips, etc. In this research, we demonstrated the effect of ultrasonic vibration drilling less than 1 mm diameter on titanium alloy. The chip generation phenomenon in the early period was captured by high-speed photography and the shapes of chips generated under various drilling conditions were compared. The results indicated that the deviation of drilled hole positions was improved due to an increase in biting performance of the chisel edge on the surface of the workpiece by ultrasonic vibration. The intermittent drilling conditions were induced when the chip load was small relative to the amplitude of vibration. Under intermittent conditions, fragmented chips were generated and tool wear was markedly reduced. Furthermore, experiments verified the effects of vibration mode of a commercial drill on burr generation, drilled hole diameter, and deviation of hole position.

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This study was performed to establish a precision belt grinding technique that can be used to process grinding surfaces with good surface roughness characteristics and a high degree of flatness with high efficiency. Due to the flexibility of the grinding belt, reduction of shape accuracy is an issue that should be improved in belt grinding. Air-floating precision belt grinding is expected to achieve this goal by floating the grinding belt with an air pressure force. Air-floating precision belt grinding was tested on SS400 steel using alumina abrasive belts. The results indicated that the grinding surface of the workpiece was formed along the pressure distribution and a high-precision grinding surface was obtained. In addition, the results of calculation of the pressure distribution on the platen by computational fluid dynamics (CFD) were qualitatively similar to those measured with a digital pressure gauge. Therefore, it was confirmed that CFD is useful to analyze the pressure distribution.

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The substrate material for electronic devices is manufactured using a multi-wire saw. These materials must be sliced in large amounts and with a high degree of accuracy. Therefore, rocking vibration-type multi-wire saws with a diamond wire tool have attracted attention by wafer makers. In such vibration multi-wire saws, the rocking vibration has a marked influence on the slicing characteristics. This study was performed to clarify the slicing mechanism of vibration slicing and the relations between vibration conditions and slicing properties. Processing was performed with different angular amplitudes of rocking vibration, and the wafer surface properties after processing were measured.

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This paper describes the influence of cutting conditions on hole shape accuracy in deep-hole machining of stainless steel with a small-diameter drill. Drilling tests were carried out by changing the feed, tool material, cutting fluid supply method, and step feed to investigate the most appropriate cutting conditions for drilling of deep holes. The results indicated that an increase in thrust force leads to buckling of the drill and work hardening of the workpiece causes tool failure. To solve these problems, cutting conditions with no buckling and high straightness were investigated. Finally, drilling a hole with L/D = 100 (diameter: 2 mm, hole depth: 200 mm) was achieved.

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