Dynamic corrosion behavior of AZ80 magnesium alloy with different orientations in simulated body fluid

• Published in: Materials chemistry and physics 2021-02, Vol.259, p.124039, Article 124039
• Main Authors: Zhu, Tao, Yu, Yi, Yang, Jie, Shen, Yongshui, He, Liuyong, Xiong, Ying
• Format: Article
• Language: English
• Subjects: Anisotropy; Biomedical materials; Body fluids; Computational fluid dynamics; Corrosion behavior; Corrosion effects; Corrosion rate; Corrosion resistance; Corrosion resistant alloys; Dynamic; EIS; Electrochemical corrosion; Electrochemical impedance spectroscopy; Flow velocity; Immersion tests (corrosion); In vitro methods and tests; Localized corrosion; Magnesium alloy; Magnesium alloys; Magnesium base alloys; Mass transfer; Shear stress; Simulated body fluid; Simulation; Spectrum analysis; Submerging
• ISSN: 0254-0584; 1879-3312
• DOI: 10.1016/j.matchemphys.2020.124039

Two specimens were prepared along the normal (ND) and transverse (TD) directions of the AZ80 magnesium alloy rolled sheet, respectively, and the other specimen was prepared along the normal direction at 45° (ND45). Three specimens (ND, ND45 and TD) were immersed in dynamic immersion equipment for in-situ electrochemical test. Electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) were used to investigate the static and dynamic corrosion behavior of the specimens in simulated body fluid (SBF). The results indicated that the specimens with different orientations exhibited anisotropy of corrosion performance. The electrochemical corrosion resistance of the specimens decreased in the following order: TD > ND45 > ND. The electrochemical corrosion resistance of the specimens decreased with increasing flow rate. The specimens immersed in SBF solution suffered localized corrosion, and the corrosion degree at the edge position of the specimen was higher than that at the middle position in dynamic environment. Computational fluid dynamics (CFD) simulations showed that with the increase of flow rate, the increase of shear stress and mass transfer coefficient led to the intensification of localized corrosion. The effect of initial texture and flow rate on the corrosion behavior of magnesium alloy was discussed. Two specimens were prepared along the normal (ND) and transverse (TD) directions of the AZ80 magnesium alloy rolled sheet, respectively, and the other specimen was prepared along the normal direction at 45° (ND45). Three specimens (ND, ND45 and TD) were immersed in dynamic immersion equipment for in-situ electrochemical test. Electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) were used to investigate the static and dynamic corrosion behavior of the specimens in simulated body fluid (SBF). The results indicated that the specimens with different orientations exhibited anisotropy of corrosion performance. The electrochemical corrosion resistance of the specimens decreased in the following order: TD > ND45 > ND. The electrochemical corrosion resistance of the specimens decreased with increasing flow rate. The specimens immersed in SBF solution suffered localized corrosion, and the corrosion degree at the edge position of the specimen was higher than that at the middle position in dynamic environment. Computational fluid dynamics