title: Electrochemical and surface analyses of nanostructured Ti-24Nb-4Zr-8Sn alloys in simulated body solution.
abstract: The use of nanostructuring to improve the stability of passive thin films on biomaterials can enhance their effectiveness in corrosion resistance and reduce the release of ions. The thickness of the ultrathin films that cover Ti and Ti alloys (only several nanometers) has prevented researchers from establishing systematic methods for their characterization. This study employed a multifunctional biomedical titanium alloy Ti-24Nb-4Zr-8Sn (wt.%) as a model material. Coarse-grained (CG) and nanostructured (NS) alloys were analyzed in 0.9% NaCl solution at 37°C. To reveal the details of the passive film, a method of sample preparation producing a passive layer suitable for transmission electron microscope analysis was developed. Electrochemical corrosion behavior was evaluated by potentiodynamic polarization tests and Mott-Schottky measurements. Surface depth chemical profile and morphology evolution were performed by X-ray photoelectron spectroscopy and in situ atomic force microscopy, respectively. A mechanism was proposed on the basis of the point defect model to compare the corrosion resistance of the passive film on NS and CG alloys. Results showed that the protective amorphous film on NS alloy is thicker, denser and more homogeneous with fewer defects than that on CG alloy. The film on NS alloy contains more oxygen and corrosion-resistant elements (Ti and Nb), as well as their suboxides, compared with the film on CG alloy. These characteristics can be attributed to the rapid, uniform growth of the passive film facilitated by nanostructuring.
authors.affiliation: Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang 110016, People's Republic of China.
authors.forename: J
authors.initials: J
authors.lastname: Li
authors.affiliation: Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang 110016, People's Republic of China.
authors.forename: S J
authors.initials: SJ
authors.lastname: Li
authors.affiliation: Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang 110016, People's Republic of China. Electronic address: ylhao@imr.ac.cn.
authors.forename: Y L
authors.initials: YL
authors.lastname: Hao
authors.affiliation: Department of Dentistry, National Yang-Ming University, Taipei, Taiwan.
authors.forename: H H
authors.initials: HH
authors.lastname: Huang
authors.affiliation: Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang 110016, People's Republic of China.
authors.forename: Y
authors.initials: Y
authors.lastname: Bai
authors.affiliation: Department of Prosthodontics, School of Stomatology, China Medical University, Shenyang 110002, People's Republic of China.
authors.forename: Y Q
authors.initials: YQ
authors.lastname: Hao
authors.affiliation: Department of Orthopaedics, Xijing Hospital, Fourth Military Medical University, Xi'an 710032, People's Republic of China.
authors.forename: Z
authors.initials: Z
authors.lastname: Guo
authors.affiliation: Department of Mechanical and Power Engineering, East China University of Science and Technology, Shanghai 200237, People's Republic of China.
authors.forename: J Q
authors.initials: JQ
authors.lastname: Xue
authors.affiliation: Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang 110016, People's Republic of China.
authors.forename: R
authors.initials: R
authors.lastname: Yang
mesh_terms: D000497:Alloys; D018625:Microscopy, Atomic Force; D046529:Microscopy, Electron, Transmission; D008954:Models, Biological; D049329:Nanostructures; D056951:Photoelectron Spectroscopy; D013499:Surface Properties
chemical_list: D000497:Alloys; C548656:Ti-24Nb-4Zr-7.9Sn alloy
keywords: Corrosion behavior; Nanostructure; Passive film; Titanium alloys