| Autor: |
Li, Yu, Sun, Yuhan, Cheng, Long, Yuan, Yue, Jia, Baohai, He, Jiaqing, Lu, Guang-Hong, Luo, Guang-Nan, Zhu, Qiang |
| Předmět: |
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| Zdroj: |
Nuclear Fusion; Dec2022, Vol. 62 Issue 12, p1-11, 11p |
| Abstrakt: |
With great power comes great challenges. For nuclear fusion, the holy grail of energy, taming the flame of a miniature star in a solid container remains one of the most fundamental challenges. A tungsten armour for the solid container marks a temporary triumphâ€"a solution adopted by the world’s largest fusion experiment, ITERâ€"but may be insufficient for future challenges. High-entropy alloys (HEAs), which are characteristic of a massive compositional space, may bring new solutions. Here, we explore their potential as plasma-facing materials (PFMs) with a prototype W57Ta21V11Ti8Cr3 HEA that was designed by exploiting the natural-mixing tendency among low-activation refractory elements. Revealed by x-ray diffraction analysis and energy-dispersive x-ray spectroscopy, it predominantly consists of a single bcc-phase but with V, Ti, and Cr segregation to grain boundaries and at precipitates. Its yield strength improves âĽ60% at room temperature and oxidation rate reduces âĽ6 times at 1273 K, compared with conventionally used W. The Tiâ€"Vâ€"Cr rich segregations and the formed CrTaO4 compound contribute to the improved oxidation resistance. However, the Tiâ€"Vâ€"Cr rich segregations, along with the decreasing valence-electron concentration of the matrix by the addition of Ta, V and Ti elements, considerably increase the deuterium retention of the W57Ta21V11Ti8Cr3 HEA to âĽ675 multiples of recrystallized W. Moreover, its thermal conductivity decreases, being âĽ40% of W at 973 K. However, the maximum tolerable steady-state heat load is still âĽ84% of W because of its exceedingly high yield strength at elevated temperatures. Overall, despite being preliminary, we expect HEAs to play an important role in the development of advanced PFMs, for their disadvantages are likely to be compensated by their advantages or be overcome by composition optimization. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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