Zirconia ceramics are often used in electronics, aerospace, biomedicine, and other fields because of their excellent mechanical and optical properties; however, as they are hard and brittle materials, they are highly susceptible to cracking and chipping during processing. Ultrasonic elliptical vibratory-assisted cutting (UEVC) is a promising ceramic processing technology that addresses existing problems in materials processing. In this study, the critical depth of cut ( \(h_{{\text{c}}}\) ) of zirconia ceramics was predicted using two models, focusing on the influence of the circular edge of the tool and tool front angle in the actual machining process. Subsequently, a model was established based on the specific cutting energy to predict the \(h_{{\text{c}}}\) of zirconia ceramics in UEVC machining. A simulation software was used to simulate the variable depth of zirconia ceramics using the constitutive improved Johnson-Holmquist ceramic (JH-2) model. Finally, the relationship between the cutting speed and \(h_{{\text{c}}}\) of zirconia ceramics under conventional cutting (CC) and UEVC machining was investigated using scribing experiments. The results showed that the \(h_{{\text{c}}}\) of zirconia ceramics decreased nonlinearly with increasing cutting speed. The \(h_{{\text{c}}}\) of zirconia under CC is 0.8 μm, whereas the \(h_{{\text{c}}}\) values of zirconia under UEVC machining are 1.79, 1.75, 1.45, and 1.3 μm with a maximum increment of 124%, which corroborates the results predicted by the model, verifying the effectiveness of the model and simulation.
