J. Mater. Sci. Technol. ›› 2020, Vol. 37: 104-113.DOI: 10.1016/j.jmst.2019.07.032

• Research Article • Previous Articles     Next Articles

Enhanced protective coatings on Ti-10V-2Fe-3Al alloy through anodizing and post-sealing with layered double hydroxides

Lei Liua, Liang Wuab*(), Xiaobo Chenc, Deen Sunab, Yuan Chenab, Gen Zhanga, Xingxing Dinga, Fusheng Panab   

  1. a College of Materials Science and Engineering, Chongqing University, Chongqing 400044, China
    b National Engineering Research Center for Magnesium Alloys, Chongqing University, Chongqing 400044, China
    c School of Engineering, RMIT University, City Campus, Carlton, VIC, 3053, Australia
  • Received:2019-05-11 Revised:2019-06-28 Accepted:2019-07-01 Published:2020-01-15 Online:2020-02-10
  • Contact: Wu Liang

Abstract:

Anodic oxidation is a prevalent technique to introduce superior corrosion and wear resistance upon the surface of titanium (Ti) alloys, in which the selection of appropriate electrolytes and defect-sealing strategies is a key. This study aims to address such issues through anodizing Ti-10V-2Fe-3Al alloy in malic acid, followed by a post-sealing treatment with Mg-Al layered double hydroxides (LDHs). The characteristics of the samples were investigated using scanning electron microscopy (SEM), atomic force microscopy (AFM), glow discharge optical emission spectroscopy (GDOES), X-ray diffraction (XRD) and energy-dispersive X-ray spectroscopy (EDS). SEM micrographs reveals that the anodic coating had a surface full of bulges and cracks, and was almost sealed by the following LDHs treatment. XRD pattern indicate that the anodic coating was mainly consisted of amorphous TiO2 with a small fraction of anatase, but its crystallization degree was increased through the post-sealing. Moreover, electrochemical and tribological measurements demonstrate that corrosion current density was 2.8 × 10-6, 2.0 × 10-7, 5.9 × 10-9 A cm-2, and wear rate was 1.45 × 10-3, 1.30 × 10-4 and 6.90 × 10-5 mm3 N-1 m-1 for respective bare Ti-10V-2Fe-3Al alloy substrate, anodized specimens without and with the LDHs post treatment. Finally, a plausible wear mechanism was proposed.

Key words: Titanium alloy, Malic acid, Layered double hydroxides, Sealing, Corrosion resistance, Tribological properties