About this Abstract |
Meeting |
2021 AWS Professional Program
|
Symposium
|
2021 AWS Professional Program
|
Presentation Title |
The Characteristics Analysis of Solidification and Microstructure in the Laser Welding of Aluminum Alloy by Phase-Field Simulation |
Author(s) |
Yuewei Ai, Yi Huang, Long Yu, Xiaoying Liu |
On-Site Speaker (Planned) |
Yi Huang |
Abstract Scope |
The mechanical performance of the welded joints is highly related to the microstructure of weld in the aluminum alloy laser welding. The complicated solidification behaviors during the welding process play a major role in the microstructure formation. This paper is focused on the dendrites evolution in the solidification process of the laser welding of 2A14 aluminum alloy. A phase field model coupled with multi-field which takes the molten metal flowing and transient macroscopic temperature field into consideration is proposed. The effects of different laser powers and welding speeds on growth morphology and solute field distribution about columnar crystals are investigated quantitatively. The simulated results are compared with the literature and experimental results and good agreement has been found. It is demonstrated that the flow field of molten pool has great effect on the growth process of columnar crystals. With the increase of the flow velocity of molten metal in the welding pool, the growth speed of columnar crystal is becoming faster and the peak of solute field increases significantly due to the local supercooling formation in the molten pool and solute precipitation. The secondary dendrites are sequentially developed. Furthermore, the growth morphology and dendrite spacing of columnar crystal are affected by the variation of flow field direction. The proposed phase field model can be used for reducing the internal welding structure defects and selecting optimal welding process of desired weld with excellent microstructure and performance. |
Proceedings Inclusion? |
Definite: Other |