Nanocrystalline zinc titanate coatings for corrosion protection

Nanocrystalline zinc titanate (ZnTiO3)coatings were deposited by atomic layer deposition (ALD) on AISI 52100 steel to study ZnTiO3 corrosion protection. The main aim of this study was to determine how the coating can inhibit pitting formation of 52100 steel in both saline solution and simulated body fluid (SBF) media. Potentiodynamic polarization tests revealed increasing corrosion potentials for the ALD ZnTiO3-coated steel specimens with protective efficiencies of 83 and 73% in saline solution and SBF, respectively. Atomic force microscopy analysis of both the ZnTiO(3)a-coated and uncoated steel revealed a high surface potential value for the ZnTiO3-coated sample as compared to the uncoated sample with a relatively low surface potential. The corrosion rates for the coated steels in both media were calculated and observed to drop by an order of magnitude. Due to the conformality, homogeneity and density of the ALD ZnTiO3 coatings, migration of Cl- and OH- ions from the electrolytes were inhibited resulting in the improved corrosion resistance.