Study on the Low-Damage Mechanism of Green ZrO2 Ceramics Under Ultrasonic Elliptical Vibration-Assisted Cutting.

Ultrasonic elliptical vibration was applied to the machining of green ZrO2 ceramics to investigate its effects on surface damage and tool wear. The experimental results were validated using discrete element simulations. Compared with conventional cutting, ultrasonic elliptical vibration-assisted cutting (UEVC) reduces surface roughness. The maximum reduction reaches 23.20% at a depth of cut of 0.8 mm and 25.39% at a cutting speed of 300 m/min. In addition, it reduces the average flank wear width by 11.5%. A substantial decrease in tangential force is observed at a depth of cut of 0.8 mm, an ultrasonic amplitude of 4 µm, and higher cutting speeds. Although the thickness of the surface compaction layer increases with cutting depth, UEVC reduces it by up to 59.33% at a depth of 0.8 mm. The PFC2D simulations predict lower subsurface residual stress magnitudes under UEVC than under CT. The chips generated during machining change from block-shaped chips under conventional cutting to powder-shaped chips under UEVC. This transformation facilitates chip removal. In addition, UEVC suppresses abrasive wear by minimizing scratching of the tool flank face from hard particles.