The motion model of the contact between abrasive particle and workpiece in two-dimension ultrasonic vibration grinding was analyzed, the maximum cutting depth of a grain were obtained. Based on indentation fracture mechanics, the critical condition of ultrasonic vibration grinding brittle-ductile transition was analyzed theoretically. The ultrasonic vibration and conventional diamond grinding of Al2O3-ZrO2(n) ceramics were performed in order to investigate the effect of ultrasonic vibration grinding conditions on the brittle-ductile transition mechanism, the micro-topography of the grinding surface were observed by AFM and SEM. Experiment results indicated that only when the maximum cutting depth of a grain less than critical depth, ductile regime grinding of ceramics can be realized, the grit size, workpiece velocity and grinding depth can affect the brittle-ductile transition.
