目的 结合超声振动加工方法，探究工程陶瓷预压应力加工过程的工件表面损伤特性。方法 建立预压应力下工程陶瓷超声振动辅助加工过程的工程学模型，结合Al2O3陶瓷划痕过程的离散元仿真结果和实验结果进行分析，采用扫描电镜对加工表面进行观察，使用三向动态压电测力仪测量划痕力。结果 预压应力下超声振动辅助划痕过程能够去除沟槽边缘处的材料堆积，并且划痕沟槽边缘破碎呈现周期性。当预压应力为200 MPa、理论划痕深度为10 μm时，普通划痕深度为7.58 μm，宽度107.5 μm，超声振动辅助划痕深度为8.55 μm，宽度为143.5 μm。结合仿真结果，超声振动辅助划痕过程可减小划痕沟槽的径向裂纹数量，增大径向裂纹深度。同时，两种划痕过程动态切向力出现明显差异，超声振动辅助划痕过程动态切向力较小，变化相对平稳。结论 超声振动辅助加工过程可以减小工程陶瓷预压应力加工过程的切削力，提高材料加工效率。

The work aims to explore the surface damage characteristics of the workpiece in the compressive prestress ma-chining process of engineering ceramics in combination with ultrasonic vibration machining method. An engineering model of ultrasonic vibration assisted machining process of engineering ceramics under compressive prestress was established. Based on the discrete element simulation results and experimental results of Al2O3 ceramic scratch process, the machined surface was observed by scanning electron microscope, and the scratch force was measured by three-dimensional dynamic piezoelectric dynamometer. The fracture of groove profile showed a periodic trend during the ultrasonic vibration under compressive prestress and the materials pilling up on the edge of the scratching-groove were constrained. When the prestress was 200 MPa and scratching depth was 10 μm, the actual scratching depth and groove width of normal scratching process were 7.58 μm and 107.5 μm, respectively, while those of ultrasonic assisted scratching process were 8.55 μm and 143.5 μm. With the simulation results, the ultrasonic assisted scratching process could decrease the number of radial cracks, but increase the depth. What’s more, the tangential forces of the both scratching processes showed obvious discrepancy. The ultrasonic assisted scratching process had the lower tangential force which fluctuated more steadily. Ultrasonic vibration assisted machining process can reduce the cutting force in the prestress machining process of engineering ceramics and improve the machining efficiency of materials.