Preparation and tribological properties of sol-gel zirconia thin films stabilized with ceria

High oriented ceria-stabilized zirconia (CSZ) thin films were prepared by the sol-gel method using zirconium oxychloride octahydrate and cerium chloride hexahydrate as starting materials. The morphology and microstructure of the films were investigated via X-ray diffractometry (XRD), X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM) and scanning electron microscopy (SEM). The films contained only tetragonal phase and showed nanoscale uniformity. Tribological properties were investigated by using a one-way reciprocating tribometer. Under low load (0.05 N), the films displayed excellent tribological properties in sliding against Si₃N₄ balls. The friction coefficient was as low as 0.15-0.19 and the wear life was more than 5000 sliding cycles. The tribological properties of CSZ/AISI52100 steel system was inferior to CSZ/Si₃N₄ system. The wear mechanism of CSZ films in sliding against Si₃N₄ under low load was fatigue wear, slight abrasion and scuffing, whereas that of in sliding against AISI52100 steel was abrasive wear and plastic deformation.