A high temperature W2B–W composite for fusion reactor shielding
File(s)
Accepted version
Author(s)
Athanasakis, Michail
Ivanov, Eugene
del Rio, Eduardo
Humphry-Baker, Samuel A
Type
Journal Article
Abstract
We have developed a new material for neutron shielding applications where space is restricted. W2B is an excellent attenuator of neutrons and gamma-rays, due to the combined gamma attenuation of W and neutron absorption of B. However, its low fracture toughness (3–4 MPa m1/2) and high melting point (2670 °C) prevent the fabrication of large fully-dense parts with adequate mechanical properties. Here we meet these challenges by combining W2B with a minor fraction (43 vol%) of metallic W. The material was produced by reaction sintering W and BN powders. The mechanical properties under flexural and compressive loading were determined up to 1900 °C. The presence of the ductile metallic W phase enabled a peak flexural strength of ∼850 MPa at 1100 °C, which is a factor of 2–3 higher than typical monolithic transition-metal borides. It also enabled a ductile-brittle transition temperature of ∼1000 °C, which is not observed in monolithic borides. Compression tests showed hardening below ∼1500 °C and significant elongation of the phase domains, which suggest that by forging or rolling, further improvements in ductility may be possible. These results have implications for W2B–W shield design; neutronics performance will likely improve with increased boron content, however this study suggests mechanical properties and manufacturability will degrade.
Date Issued
2020-04-15
Date Acceptance
2020-02-13
Citation
Journal of Nuclear Materials, 2020, 532, pp.1-10
ISSN
0022-3115
Publisher
Elsevier BV
Start Page
1
End Page
10
Journal / Book Title
Journal of Nuclear Materials
Volume
532
Copyright Statement
© 2020 Elsevier Ltd. All rights reserved. This manuscript is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International Licence http://creativecommons.org/licenses/by-nc-nd/4.0/
Identifier
https://www.sciencedirect.com/science/article/pii/S0022311519315326?via%3Dihub
Subjects
Energy
0912 Materials Engineering
Publication Status
Published
Article Number
152062
Date Publish Online
2020-02-15