Effects of C, N-codoped on the corrosion resistance of TiO2 films prepared by plasma surface alloying and thermal oxidation duplex process

Abstract

C, N-codoped TiO2 films have been deposited onto stainless steel substrates using plasma surface alloying and thermal oxidation duplex process. Composition analysis shows that the films shield the substrates entirely. The TiO2 films are anatase in structure as characterized by X-ray diffraction. The electrochemical measurements show that the equilibrium corrosion potential positively shifts from −0.275 eV for bare stainless steel to −0.267 eV for C, N-codoped TiO2 coated stainless steel, and the corrosion current density decreases from 1.3×10−5 A/cm2 to 4.1×10−6 A/cm2. The corrosion resistance obtained by electrochemistry noise also reveals that the C, N-codoped TiO2 films provide good protection for stainless steel against corrosion in stimulated body fluid. The above results indicate that C, N-codoped TiO2 films deposited by plasma surface alloying and thermal oxidation duplex process are effective in protecting stainless steel from corrosion.