The micro-route grinding system was developed for efficient micro-cutoff and micro-slotting of fine ceramics. However, because of the use of a very thin electroplated diamond quill, it has several problems in the machining performance : elastic deflection and fracture of the quill, and chipping and large cutoff-surface roughness. To solve these problems, ultrasonic vibration was applied to the workpiece perpendicularly to the machining direction. The obtained results from some cutoff experiments of Sr-Ferrite ceramics are summarized as follows. (1) By means of ultrasonic vibration, the grinding force is decreased by about 30% at the maximum, and the number of large-size chippings on the upper edge of the cutoff workpiece surface is decreased. Furthermore, the ten-point average roughness Rz of the cutoff workpiece surface measured in the quill axis direction is decreased by about 30%. (2) In the case that a quill cuts off a workpiece while rotating in a clockwise direction, the quill deflects backward to the left of the cutting direction. Here, the deflection size is decreased by ultrasonic vibration, and the cutoff accuracy is enhanced. (3) In the case of the use of an eccentric quill, the width of the obtained cut-out groove is increased by ultrasonic vibration.
