Improvement in corrosion resistance of CrN coated stainless steel by conformal TiO2 deposition

A conformal titanium dioxide (TiO2) layer was deposited onto chromium nitride (CrN) coated stainless steel by atomic layer deposition technique, and the electrochemical corrosion test on the CrN single-layer and TiO2/CrN double-layer coated sample was carried out. The equilibrium corrosion potential of the double-layer coated sample shifted positively compare to that of the single-layer coated one. Moreover, the corrosion current density decreased significantly with the TiO2 deposition, revealing that better corrosion resistance was obtained after the deposition of the TiO2 layer. The improvement in corrosion resistance after the TiO2 deposition was attributed to the blocking of the through-thickness cracks or pinholes in the CrN layer.