ZrO2 ceramic has a wide range of applications, such as in the thermal barrier coating (TBC) of turbine blades, micro actuators, and gas sensors. However, this material is challenging to machine due to its high hardness and brittleness. Although spark assisted chemical engraving (SACE) can be used to machine ZrO2 ceramics, the traditional SACE models for glass are difficult to apply to ZrO2 ceramics since the melting point of ZrO2 is much higher than that of glass. A theoretical basis for applying the SACE process to ZrO2 ceramics is still lacking, which makes applying the SACE process to machine micro cavities with high surface quality in ZrO2 ceramics very challenging. This paper proposes an energy action model based on the processing voltage, pulse width and machining gap by analyzing the energy transfer process of SACE. The energy model expresses difference in the spark energy between physical removal and chemical removal. Through machining experiments, the contact effect of the SACE process on ZrO2 ceramics was found, and the reasons why the SACE process is sensitive to the machining gap were clarified. Furthermore, physical and chemical removal process models with or without the discharge constraint onto the end of the tool electrode were established. Using the above theoretical models, a circular ring microcavity without micro cracks on surface was achieved in a ZrO2 ceramic workpiece by using the SACE process with the regulating energy effect trending to the chemical removal. Additionally, considering the contact effect and the process models applied in the SACE scanning process of ZrO2 ceramics, a tool electrode with a spring structure was employed to solve the bending problem of the micro tool electrode. As a result, a square micro-cavity with high surface quality was machined successfully.

中文翻译：

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提高ZrO ₂陶瓷微孔表面质量的火花辅助化学雕刻（SACE）能量作用模型

ZrO2 陶瓷具有广泛的应用，例如在涡轮叶片、微执行器和气体传感器的热障涂层 (TBC) 中。然而，这种材料由于其高硬度和脆性而难以加工。虽然火花辅助化学雕刻 (SACE) 可用于加工 ZrO2 陶瓷，但传统的玻璃 SACE 模型难以应用于 ZrO2 陶瓷，因为 ZrO2 的熔点远高于玻璃的熔点。目前尚缺乏将 SACE 工艺应用于 ZrO2 陶瓷的理论基础，这使得应用 SACE 工艺在 ZrO2 陶瓷中加工具有高表面质量的微腔非常具有挑战性。本文通过分析SACE的能量传递过程，提出了一种基于加工电压、脉冲宽度和加工间隙的能量作用模型。能量模型表示物理去除和化学去除之间火花能量的差异。通过机加工实验，发现了SACE工艺对ZrO2陶瓷的接触效应，阐明了SACE工艺对加工间隙敏感的原因。此外，建立了带有或不带有工具电极末端放电约束的物理和化学去除过程模型。利用上述理论模型，通过调节能量效应趋向于化学去除的SACE工艺，在ZrO2陶瓷工件中获得了表面无微裂纹的圆环微腔。此外，考虑到接触效应和应用于 ZrO2 陶瓷 SACE 扫描工艺的工艺模型，采用弹簧结构的工具电极解决了微型工具电极的弯曲问题。结果，成功加工出具有高表面质量的方形微腔。