Microstructure Evolution of Ti-45Al-8.5Nb-0.2W-0.2B-0.02Y Alloy during Long-Term Thermal Exposure
Abstract
:1. Introduction
2. Materials and Methods
3. Results
3.1. BSE Images of Unexposed and Exposed Microstructures
3.2. TEM Examination of Unexposed Microstructures
3.3. Observation of Microstructure Changes during 10,000 h Exposure by Transmission Electron Microscopy
3.3.1. Bulk and Flaky Large γ Grains Appear after 5000 h and Exposure
3.3.2. A Large Amount of B2(ω) is Precipitated at the α2 + γ Lamellae Boundary and the γ/γ Interfaces during Long-Term Exposure
3.3.3. The γ Phase Precipitated in the B2 Area after 5000 and 10,000 h Exposure
4. Discussion
5. Conclusions
Author Contributions
Funding
Conflicts of Interest
References
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Exposure Time (h) | Volume Fraction (%) | Size (μm) | ||||
---|---|---|---|---|---|---|
B2(ω) | Equiaxial γ | α2 +γ Lamella | B2(ω) | Equiaxial γ | α2 +γ Lamella | |
0 | 2.2 ± 0.3 | 57.6 ± 3.2 | 40.2 ± 3.5 | 10.3 ± 1.5 | 20.9 ± 3.4 | 36.2 ± 1.3 |
3000 | 3.7 ± 0.4 | 58.5 ± 4.1 | 37.8 ± 4.2 | 16.4 ± 3.2 | 23.3 ± 1.6 | 45.5 ± 2.7 |
5000 | 6.5 ± 0.2 | 61.3 ± 3.7 | 32.3 ± 3.8 | 24.4 ± 2.7 | 27.2 ± 2.3 | 32.3 ± 2.4 |
10,000 | 16.8 ± 2.4 | 63.2 ± 4.3 | 20.0 ± 4.3 | 28.8 ± 1.1 | 47.5 ± 3.8 | 26.6 ± 3.5 |
Element | Composition of Major Constituents (at. %) | Partition Factor k | ||||
---|---|---|---|---|---|---|
β (B2 + ω) | γ | α2 | K(β/γ) | K(β/α2) | K(α2/γ) | |
Ti | 52.6 ± 1.2 | 44.5 ± 0.9 | 52.5 ± 0.8 | 1.18 | 1.00 | 1.17 |
Al | 34.4 ± 0.4 | 46.0 ± 0.8 | 37.8 ± 0.7 | 0.75 | 0.91 | 0.82 |
Nb | 12.1 ± 0.2 | 9.2 ± 0.3 | 9.4 ± 0.2 | 1.32 | 1.29 | 1.02 |
W | 0.9 ± 0.2 | 0.3 ± 0.1 | 0.3 ± 0.1 | 3.00 | 3.00 | 1.00 |
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Chen, Z.; Cai, Z.; Jiang, X.; Chen, S.; Huang, Z.; Sun, H. Microstructure Evolution of Ti-45Al-8.5Nb-0.2W-0.2B-0.02Y Alloy during Long-Term Thermal Exposure. Materials 2020, 13, 1638. https://doi.org/10.3390/ma13071638
Chen Z, Cai Z, Jiang X, Chen S, Huang Z, Sun H. Microstructure Evolution of Ti-45Al-8.5Nb-0.2W-0.2B-0.02Y Alloy during Long-Term Thermal Exposure. Materials. 2020; 13(7):1638. https://doi.org/10.3390/ma13071638
Chicago/Turabian StyleChen, Zhiyuan, Zhengkun Cai, Xiaosong Jiang, Song Chen, Zewen Huang, and Hongliang Sun. 2020. "Microstructure Evolution of Ti-45Al-8.5Nb-0.2W-0.2B-0.02Y Alloy during Long-Term Thermal Exposure" Materials 13, no. 7: 1638. https://doi.org/10.3390/ma13071638