Zirconia ceramics are promising materials for restoration and are widely used in the field of artificial teeth. However, wear resistance affects the longevity of artificial teeth. In this study, peacock tail feather micro-textures and groove micro-textures are prepared on the surfaces of zirconia ceramics via the laser ablation technique to improve their tribological properties. The effects of micro-textures on the surface wettability and tribological properties of zirconia ceramics are studied. The micro-textures improve the surface wettability and tribological properties of zirconia ceramics. The average coefficient of friction of peacock tail feather micro-textured samples decreases by 53% compared to that of the samples without micro-textures. Different operating conditions affect the friction properties of zirconia ceramics. The samples have the best friction performance when the rotational speed, load, and acid/alkaline environment are 200 r/min, 15 N, and weakly alkaline, respectively. Furthermore, the mechanism by which surface micro-textures reduce frictional wear is as follows: the textured grooves store debris, and the bottom edge of the textured groove acts as a cutting tool to cut debris, preventing debris from scratching the surface. The micro-textures store lubricant and form a liquid film on the ceramic surface to reduce wear.
ZrO2 ceramics, known for their high strength and wear resistance, are ideal for artificial joints. This study enhanced the friction performance of these joints by fabricating textured structures (50 μm width and 20–25 μm depth) on the ceramic surface. Friction tests, conducted at 200 r/min for 30 min with a 5–20 N load and lubricant concentration of 15–60 mg/mL using PEEK balls, showed that textured joints outperformed untextured ones. The symmetrical triangular structure had the lowest coefficient of friction and the best hydrophilicity, with a 53.0% reduction in the coefficient of friction and a 57.4% reduction in the contact angle compared to the untextured structure. The textures effectively store the PEEK residue and facilitate the smooth movement of the worn ball. Concurrently, the textured structure stores some of the lubricant, which reduces the static pressure during fluid flow by 12.6%. Overall, the friction performance of ZrO2 ceramic artificial joints was significantly improved by the textured structures.
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.