Effect of sol aging time on the wear properties of TiO2-SiO2 composite films prepared by a sol-gel method

TiO2-SiO2 composite films were deposited on commercially pure titanium (Cp-Ti) substrate with composite sols of different aging times (unaged, 1, 3, 10 weeks) by a sol-gel method. The effects of aging time on the structural, mechanical and wear properties of composite coatings were investigated using pin-on-disk tribotester. The structure of composite coatings was analyzed with XRD and SEM. The wear volume of TiO2-SiO2 composite films were investigated with 3D profilometer. Tribological properties of the composite films were significantly influenced by aging time. Composite coatings prepared from unaged sol showed the best wear resistance. This may be attributed to their high surface hardness, low surface roughness and self-lubricant phase structure. It was observed that increasing aging time led to increase the grain size. It was obtained that the wear volume values increased with increasing aging time.