Design and investigation of TiO۲ –SiO۲ thin films on AISI ۳۱۶L stainless steel for tribological properties and corrosion protection

The TiO۲–SiO۲ thin films were deposited on AISI ۳۱۶L stainless steel via sol-gel method. Then, the effect of the added amount of SiO۲ on the structure, morphology and mechanical properties of the films and corrosion behavior of AISI ۳۱۶L stainless steel substrate were investigated. So, X-ray diffraction, field-emission scanning electron microscopy, atomic force microscopy, depth-sensing indentation technique supporting micro-scratch mode and potentiodynamic polarization test were used. It was observed that the appropriate amount SiO۲ addition into TiO۲ film not only decreased the particle size of TiO۲–SiO۲ crystal but also could help to improve the surface quality. The mechanical and tribological properties of the films were found to be improved in the range of ۱۰–۱۵%mol SiO۲ addition compared with the pure TiO۲. The minimum root mean square value was obtained from the film with a silica content of ۱۰%mol. In addition, the corrosion behavior of AISI ۳۱۶L stainless steel was improved by adding ۱۵%mol SiO۲. Under UV illumination conditions, photo-generated electrons accumulated in this film could perfectly protect the substrate photocathodically.

Keywords:

TiO۲–SiO۲ nanocomposite films , Sol-gel method , depth-sensing indentation technique , photocathodic protection effect