A feasibility study of microscale fabrication by ultrasonic-shoe centerless grinding

The present authors proposed a new centerless grinding technique, namely ultrasonic-shoe centerless grinding, which they validated experimentally in a previous study [Wu Y, Fan Y, Kato M, Wang J, Syoji K, Kuriyagawa T. A new centerless grinding technique without employing a regulating wheel. Key Eng Mater 2003;238–239:355–60]. Rather than a regulating wheel as in conventional centerless grinding, the new method uses a plate-shaped ultrasonic shoe, on the end face of which micro elliptic motion is generated, to support the workpiece and control its rotational motion. This enables the fabrication of a microscale cylindrical component less than 100 μm in diameter with an extremely large aspect ratio, which is extremely difficult to produce by conventional machining techniques. In the present study, in order to develop a novel technique for the fabrication of microscale cylindrical components, first an apparatus capable of microscale fabrication was designed and constructed based on the ultrasonic-shoe centerless grinding method. Following initial performance tests, the apparatus was tested by conducting a grinding run on a tungsten carbide test-piece, 0.6 mm in diameter and 15 mm in length. The result was a microscale cylindrical component, around 60 μm in diameter and 15 mm in length, with an aspect ratio of over 250, which validated the new technique proposed for microscale fabrication.