中國有色金屬學報(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 30 No. 10 October 2020 |
（1. Department of Mechanical Engineering, Tsinghua University, Beijing 100084, China;
2. Key Laboratory for Advanced Materials Processing Technology, Ministry of Education, Tsinghua University, Beijing 100084, China;
3. State Key Laboratory of Tribology, Tsinghua University, Beijing 100084, China;
4. China Academy of Launch Vehicle Technology, Beijing 100076, China;
5. Tianjin Long March Launch Vehicle Manufacturing Co., Ltd., Tianjin 300462, China;
6. Capital Aerospace Machinery Corporation Limited, Beijing 100076, China）
Abstract:Microstructural evolution and its effect on mechanical properties in different regions of 2219-C10S aluminum alloy tungsten inert gas (TIG) welded joint were analyzed in detail. In weld zone (WZ), α+θ eutectic structure formed at grain boundaries with no precipitates inside the grains. In partially melted zone (PMZ), symbiotic eutectic or divorced eutectic formed at grain boundaries and needle-like θ′ phases appeared in the secondary heated zone. In over aged zone (OAZ), the coarsening and dissolution of θ? phases occurred and most θ′ phases transformed into θ phases. In general heat affected zone (HAZ), θ′ phases coarsened. Factors such as the strengthening phases, the grain size, the Cu content in matrix and the dislocation density can affect the mechanical properties in different regions of the joint. Moreover, a model describing the relationship between mechanical properties of the material and the volume fraction of precipitates, the average diameter of precipitates and the concentration of soluble elements was proposed.
Key words: 2219-C10S aluminum alloy; tungsten inert gas arc welding; microstructural evolution; mechanical properties; relationship model
