Two-step vs. Single-Step Electrochemical Anodizing Process Regarding Anti-Corrosion Properties of Titanium

Document Type : Original Article

Authors

1 Faculty of Technology, Department of Renewable Energy, Blida 1 University, Soumaa, Blida 09000, Algeria

2 Chemical Engineering Laboratory, Department of Industrial Chemistry, Blida 1 University, Soumaa, Blida 09000, Algeria

3 Laboratory of Materials: Elaboration–Properties–Application, University of Jijel, Jijel 18000, Algeria

4 Faculté des Sciences, Département de chimie, Université de M'Sila, 28000 M'Sila, Algeria

5 Faculty of Technology, Department of Process Engineering, USTHB University, Babezzouar, Alger 16000, Algeria

6 Department of Chemistry Blida 1 University, Soumaa, Blida 09100, Algeria

Abstract

Two-step anodizing approach is a simple way to produce an adhesive and continuous layer while improving the stability of titanium oxide in aggressive aqueous media. A comparative study of the electrochemical behavior of TiO2 anodic films formed by single-step (SSA) and two-step (TSA) anodizing processes has been investigated. The anodic films have been characterized by SEM, EDX, GDOES, XRD, and FTIR analysis. Potentiodynamic polarization and EIS were used to investigate corrosion behavior in corrosive environments. A completely different surface morphology of anodic films has been obtained. Surface oxide film thicknesses of specimens were estimated at 51.86 and 60.67 µm for the SSA and TSA processes, respectively. In both cases, X-ray diffraction revealed an amorphous nature. EIS results showed that corrosion performance is closely related to anodic film morphology including thick layers, compactness, uniformity, and stability, as proved by the TSA process. Analysis of dynamic potential polarization confirmed that the TSA approach enhanced corrosion resistance by increasing (Ecorr) and lowering (Icorr). The corrosion potential (Ecorr) increased from -0.309 V/ECS to -0.271 V/ECS for the SSA and TSA and the Icorr value decreased from 1.410 μA.cm-2 to 1.032 μA.cm-2 for SSA and TSA approaches respectively.

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