A compact eccentric horn shape transducer body with longitudinal vibration sensor bolted to it has been developed. The device can produce an angular vibration of the order of 40 kHz at the cutting tip attached to the end of the horn. The vibrating tip was to be used for precision machining of straight micro-grooves, which are difficult to achieve using existing precision machine tools, on which the processing was at a slow speed of the order of 4m/min. The vibration features such as vibration angle and amplitude of the horn at the tool tip, observed by a CCD camera at the magnification of 1500x, were 30° and 6μm P-V, respectively. An ultrasonic vibration frequency of 57.4 kHz was achieved. The R-shaped micro-groove machining was successfully carried out on the cold rolled steel SKS93 and Hv209 in two stages, a roughing cut at a depth of cut of 20 μm, and a finishing cut of 3μm, 6μm, and 10μm, for the feed rates of 1.5 and 2.0m/min, respectively. The length was 125mm. The appearance of the machined surface is excellent compared with the torn surface obtained in conventional groove machining.
