The Effect of Potential on Surface Characteristic and Corrosion Resistance of Anodic Oxide Film Formed on Commercial Pure Titanium at the Potentiodynamic-Aging Mode.

Ling Zhang,Keyi Wei,Rui Gao,Jianyun Yang,Yanqing Duan,Tianlin Fu,Danyu Tang

doi:10.3390/ma12030370

Abstract

Anodic oxidation treatment of commercially pure titanium was carried out at the voltages of 10, 30, 50 V in 0.5 M H2SO4 solution at the potentiodynamic-aging mode so as to obtain the effects of the anodic potential on the surface characteristic and corrosion resistance of the anodic oxide film. The influences of potential on the surface morphology, the roughness, the crystalline behavior, the chemical composition and the corrosion resistance of the anodic oxide films were investigated by using scanning electron microscopy (SEM), atomic force microscope (AFM), Raman spectrum, X-ray diffractometry (XRD), X-ray photoelectron spectroscopy (XPS), potentiodynamic polarization curves and electrode impedance spectroscopy (EIS). The results show that increasing anodic potential at the potentiodynamic-aging mode can significantly enhance thickness, flatness, crystallization, chemical stability, and corrosion resistance of anodic oxide film.

Highlights

Titanium and its alloys have been extensively used in aerospace, marine engineering, biomedical applications due to their excellent properties [1]
Xing et al [23], the Raman band intensity is proportional to the film crystallinity. These results clearly show that the crystallization of passive films is enhanced by increasing the anodic potential at the potentiodynamic-aging mode
The results indicate that the anodic oxidation treatment has a positive effect of improving the corrosion resistance of commercial pure titanium (CP-Ti)

Summary

Introduction

Titanium and its alloys have been extensively used in aerospace, marine engineering, biomedical applications due to their excellent properties [1]. The excellent corrosion resistance of titanium is due to an ultra-thin amorphous film, which grows spontaneously on its surface in air and aqueous environments (Ti + O2 = TiO2 , ∆G0 = −888.8 kJ·mol−1 ) [2]. This native oxide film can prevent the metal from further reacting with corrosive environments [3]. These films have many defects, only a few nm in thickness [4]. It can be destroyed owing to many reasons, leading to crevice and galvanic corrosion [4,6]

Results

Discussion

Conclusion