中国有色金属学报(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 32 No. 5 May 2022 |
（1. Corrosion Laboratory for Light Metals, College of Materials Science and Engineering, Shandong University of Science and Technology, Qingdao 266590, China;
2. School of Engineering, RMIT University, Carlton 3053, VIC, Australia;
3. School of Chemical and Biological Engineering, Shandong University of Science and Technology, Qingdao 266590, China;
4. School of Materials Science and Engineering, Chongqing University of Technology, Chongqing 400054, China;
5. School of Materials Science and Engineering, Zhengzhou University, Zhengzhou 450002, China）
Abstract:A Schiff base (a compound containing a C=N bond) induced anodic Ca-P coating was prepared on AZ31 Mg alloy in a mixed solution of CaCl2 and KH2PO4 at 60 °C in the presence of glucose and L-cysteine. The microstructure and chemical composition of the coatings were characterized using FE-SEM, FT-IR, XRD, and XPS. The in vitro degradation resistance of the coated samples was evaluated via potentiodynamic polarization (PDP), electrochemical impedance spectroscopy (EIS), and hydrogen evolution test. The experimental results show that the Ca-PSchiff base coating is composed of CaHPO4 (DCPA) and hydroxyapatite (HA), whereas HA is not present in the Ca-P coating. The Ca-PSchiff base coating thickness is about 2 times that of Ca-P coating (Ca-P coating: (9.13±4.20) μm and Ca-PSchiff base: (18.13±5.78) μm). The corrosion current density of the Ca-PSchiff base coating is two orders of magnitude lower than that of the Ca-P coating. The formation mechanism of the Ca-PSchiff base is proposed.
Key words: magnesium alloy; anodic coating; corrosion resistance; Schiff base; biomaterial
