Effect of gadolinium addition on the corrosion behavior and oxide properties of titanium in boric acid solution at 50 °C
Do Haeng Hur, Soon-Hyeok Jeon, Jeoh Han, Sun‐Young Park, Young-Bum Chun
Abstract
The purpose of this study is to investigate the electrochemical and immersion corrosion behavior of Ti-5 wt.% Gd alloy in a boric acid solution at 50 °C. The chemical states and defect densities of oxide films formed in the solution were determined using X-ray photoelectron spectroscopy and the Mott–Schottky relation, respectively. Ti-5Gd alloy revealed a higher corrosion and passive current density, and greater weight loss compared to pure Ti, which is primarily attributed to the preferential dissolution of anodic Gd-rich particles in the cathodic Ti matrix. Incorporation of Gd3+ ions into the TiO2 lattice increased oxygen vacancy concentration; therefore, the oxide films of Ti-5Gd alloy contained much more point defects that carry the charges through the films, thereby deteriorating the corrosion resistance of the alloy in regards to the properties of the films.