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. College of Materials Science and Engineering, Chongqing University of Technology, Chongqing 400054, China;
2. College of Materials Science and Engineering, Chongqing University, Chongqing 400044, China;
3. College of Economics and Business Administration, Chongqing University of Education, Chongqing 400067, China;
4. Zhongke (Guangdong) Refinery & Petrochemical Company Limited, Zhanjiang 524076, China）
Abstract:In order to develop a new surface treatment technology for aluminum-lithium alloys, an AA2099-T83 alloy was anodized in a tartaric-sulfuric acid bath and then post-treated in lithium carbonate (Li2CO3) solutions of different temperature-concentration combinations. The results show that the post-treatment in Li2CO3 solutions can greatly improve corrosion resistance of the anodized alloy (withstanding up to 1300 h of neutral salt spray test). It is found that the sealing process is distinctly different for high-temperature/low-concentration and low-temperature/high- concentration combinations. Specifically, the anodic film is only partially sealed in high-temperature mode but more fully sealed in low-temperature mode. The mechanism for the high corrosion resistance of the treated alloy is ascribed to the barrier effect of the sealing products (i.e., Li-Al-LDH and/or boehmite) on the surface and in the interiors of the anodic film.
Key words: aluminum-lithium alloy; anodizing; corrosion resistance; lithium carbonate; Li-Al-LDH; sealing treatment
