中国有色金属学报(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 34 No. 6 June 2024 |
（1. Corrosion Laboratory for Light Metals, College of Materials Science and Engineering, Shandong University of Science and Technology, Qingdao 266590, China;
2. State Key Laboratory of Nonferrous Metals and Processes, GRINM Group Co., Ltd., Beijing 100088, China;
3. School of Engineering, University of Newcastle, Callaghan, New South Wales, 2308, Australia;
4. College of Chemical and Environmental Engineering, Shandong University of Science and Technology, Qingdao 266590, China;
5. School of Materials Science and Engineering, Zhengzhou University, Zhengzhou 450002, China）
Abstract:The effect of oxalic acid (OA) etching on the formation mechanism and corrosion performance of in-situ steam Mg-Al layered double hydroxide (LDH) coatings on AM50 Mg alloy was investigated by exposing the intermetallic compounds (β-Mg17Al12 and AlMn) on the surface of the alloy. The results demonstrated that the presence of OA led to an increased fraction of intermetallic compounds on the Mg substrate. Mg-Al LDH nucleated and grew around the Al-Mn phase. The best corrosion resistance of LDH coating was obtained with the maximum thickness at a pickling time of 45 s, and the corrosion current density was reduced by three orders of magnitude compared to the substrate. Finally, the formation mechanism of Mg-Al LDH coating on AM50 Mg alloy was proposed.
Key words: magnesium alloy; oxalic acid; intermetallic compound; steam coating; layered double hydroxide; corrosion resistance
