目的 揭示旋转超声振动对硬脆材料脆塑转变特性及工艺参数对材料脆塑转变临界切削深度的影响规律。方法 以氧化锆陶瓷为研究对象，在硬脆材料压痕断裂试验基础上，从理论上分析了超声振动加工硬脆材料脆塑转变的临界条件，并进行了纵向振动及纵扭共振形式的旋转超声振动划痕与普通划痕对比试验。结果 在相同试验条件下，超声振动划痕较普通划痕有较高的材料脆塑转变临界切削深度。适当地增大超声能量，纵扭共振比纵向振动具有更大的脆塑转变临界切削深度值；而随着进给速度的增大，纵向振动比纵扭共振具有更大的材料脆塑转变临界切削深度。结论 通过不同划痕条件的对比，超声振动能有效提高氧化锆陶瓷的脆塑转变临界切削深度，增大塑性域加工范围，提高材料表面加工质量，验证了理论分析的正确性。

The work aims to reveal the brittle-ductile transition characteristics of rotating ultrasonic vibration on hard-brittle materials and the influence of processing parameter on the critical cutting depth of zirconia ceramics. Based on the fracture experiment, the critical condition of brittle-ductile transition of hard-brittle materials processing by rotary ultrasonic vibration was analyzed theoretically, and the comparison testing between rotary ultrasonic vibration scratch and normal scratch was carried out. Under the same test conditions, compared with the critical cutting depth of brittle-ductile transition on normal scratch, ultrasonic vibration scratch has a higher value. The critical cutting depth of brittle-ductile transition can be effectively increased by increasing the ultrasonic energy, and the critical cutting depth of brittle-ductile transition in longitudinal-torsional resonance is higher than that in longitudinal vibration. However, the critical cutting depth of brittle-ductile transition in longitudinal vibration is greater than that in Longitudinal-torsional resonance, when the feed speed is increasing. By comparing different scratch conditions, the ultrasonic vibration can effectively improve the critical cutting depth of brittle-ductile transition, increase the machining range of ductile domain, and improve the surface quality of Zirconia Ceramics.