A Comparative Investigation on Conventional and Stationary Shoulder Friction Stir Welding of Al-7075 Butt-Lap Structure
Abstract
:1. Introduction
2. Materials and Methods
3. Results
3.1. The Macrostructures of FSW Joints
3.2. The Microstructures of FSW Foints
3.3. The Mechanical Characterizations of FSW Joints
4. Conclusions
- The surface of the joint became smooth by using S-FSW, and moreover, the SAZ of the S-FSW joint was eliminated. The material flow mode was changed by the application of stationary shoulder, resulting in the formation of the flat hook defect.
- Compared with C-FSW, the grain size in the NZ decreased and the coarsening of strengthening precipitates in the HAZ was inhibited owning to the lower welding heat input of S-FSW. And both the hardness and tensile strength of the S-FSW joint were enhanced in comparison to the C-FSW joint due to the finer microstructures.
- All the FSW joints got fractured inside the NZ because of hook defect, and the plasticity of the FSW joints was controlled by the shape of the hook defect. In comparison to the flat hook defect of the S-FSW joint, the sharp-angled hook defect decreased the total elongation of the C-FSW joint further.
Author Contributions
Funding
Conflicts of Interest
References
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Zn | Mg | Cu | Cr | Fe | Si | Mn | Al |
---|---|---|---|---|---|---|---|
5.1–6.1 | 2.1–2.9 | 1.2–2.0 | 0.2–0.3 | <0.5 | <0.4 | <0.3 | Bal. |
Samples | Yield Strength, YS (MPa) | Ultimate Tensile Strength, UTS (MPa) | Total Elongation, TE (%) |
---|---|---|---|
BM | 498 ± 5 | 556 ± 5 | 18.2 ± 0.8 |
C-FSW | 264 ± 8 | 404 ± 11 | 5.1 ± 0.4 |
S-FSW | 302 ± 3 | 445 ± 7 | 7.6 ± 0.6 |
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Chen, Y.; Li, H.; Wang, X.; Ding, H.; Zhang, F. A Comparative Investigation on Conventional and Stationary Shoulder Friction Stir Welding of Al-7075 Butt-Lap Structure. Metals 2019, 9, 1264. https://doi.org/10.3390/met9121264
Chen Y, Li H, Wang X, Ding H, Zhang F. A Comparative Investigation on Conventional and Stationary Shoulder Friction Stir Welding of Al-7075 Butt-Lap Structure. Metals. 2019; 9(12):1264. https://doi.org/10.3390/met9121264
Chicago/Turabian StyleChen, Yu, Huaying Li, Xiaoyu Wang, Hua Ding, and Fenghe Zhang. 2019. "A Comparative Investigation on Conventional and Stationary Shoulder Friction Stir Welding of Al-7075 Butt-Lap Structure" Metals 9, no. 12: 1264. https://doi.org/10.3390/met9121264