中国有色金属学报(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 19 No. 5 October 2009 |
（1. School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001, China;
2. Beijing Institute of Aeronautical Materials, Beijing 100095, China;
3. Shenyang Aircraft Plants, Shenyang 110034, China）
Abstract:Portevin-Le Chatelier (PLC) effect in a severely cold-rolled Al-Zn-Mg-Cu-Zr aluminum alloy (AA7055 type) plate before and after annealing was investigated. The results show that the sample annealed at 300 ℃ undergoes PLC effect, whereas the PLC effect is not observed in the deformed sample or the samples annealed at 110 ℃ or 200 ℃. The main precipitates in the sample annealed at 300 ℃ are the coarsened η phases, while a mixture of small η′ phases and η phases dominates in the sample annealed at 200 ℃. In the deformed sample and sample annealed at 110 ℃, GP zone are the main precipitates. The different flow behaviors are ascribed to the type of precipitates as well as the dislocation density differences.
Key words: aluminum alloy; Portevin-Le Chatelier effect; precipitation; dislocation
