Design and Investigation of TiO2 –SiO2 Thin Films on AISI 316L Stainless Steel for Tribological Properties and Corrosion Protection

The TiO2–SiO2 thin films were deposited on the AISI 316L stainless steel via the sol-gel method. Then, the effect of the added amount of SiO2 on the structure, morphology and mechanical properties of the films and corrosion behavior of the AISI 316L stainless steel substrate were investigated Bu using X-ray diffraction, field-emission scanning electron microscopy, atomic force microscopy, depth-sensing indentation technique supporting micro-scratch mode and potentiodynamic polarization test. It was observed that the appropriate amount of SiO2 addition to the TiO2 film not only decreased the particle size of the TiO2–SiO2 crystal but also could help to improve the surface quality. Mechanical and tribological properties of the films were found to be improved in the range of 10–15%mol of SiO2 addition compared with the pure TiO2. The minimum root mean square value was obtained from the film with a silica content of 10%mol. In addition, the corrosion behavior of the AISI 316L stainless steel was improved by adding 15%mol of SiO2. Under the UV illumination conditions, photo-generated electrons accumulated in this film could perfectly protect the substrate photocathodically.