Understanding the oxidation of pure tungsten in air and its impact on the lifecycle of a fusion power plant
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Author(s)
Type
Journal Article
Abstract
The oxidation of pure W and the sublimation of W oxide have been investigated to assess their impact on the
lifecycle of a fusion power plant. Pure W has been oxidised at temperatures between 400 and 1050 ◦C and for
durations ranging between 1 and 70 h. The formation of voids and cracks has been observed at temperatures
above 600 ◦C, leading to the formation of dust or oxide spalling, which could be problematic in maintenance
and waste-handling scenarios of a fusion power plant. Preferential oxidation taking place at the edge of the
specimen was characterised, and its impact is discussed in relation to component design. Characterisation using
electron microscopy and Raman spectroscopy revealed that the oxide scale is formed of three main layers: the
inner layer is 30–50 nm thick WO2 oxide, the middle layer is a 10–20 μm thick of WO2.72 and the outer layer
is formed of WO2.9/WO3 phases — whose thickness varies according to the total thickness of the oxide scale.
The observed microstructure is discussed in relation to the parabolic-to-linear kinetics and its potential impact
on tritium permeation and detritiation efficiency.
lifecycle of a fusion power plant. Pure W has been oxidised at temperatures between 400 and 1050 ◦C and for
durations ranging between 1 and 70 h. The formation of voids and cracks has been observed at temperatures
above 600 ◦C, leading to the formation of dust or oxide spalling, which could be problematic in maintenance
and waste-handling scenarios of a fusion power plant. Preferential oxidation taking place at the edge of the
specimen was characterised, and its impact is discussed in relation to component design. Characterisation using
electron microscopy and Raman spectroscopy revealed that the oxide scale is formed of three main layers: the
inner layer is 30–50 nm thick WO2 oxide, the middle layer is a 10–20 μm thick of WO2.72 and the outer layer
is formed of WO2.9/WO3 phases — whose thickness varies according to the total thickness of the oxide scale.
The observed microstructure is discussed in relation to the parabolic-to-linear kinetics and its potential impact
on tritium permeation and detritiation efficiency.
Date Issued
2025-12-01
Date Acceptance
2025-09-12
Citation
Nuclear Materials and Energy, 2025, 45
ISSN
2352-1791
Publisher
Elsevier BV
Journal / Book Title
Nuclear Materials and Energy
Volume
45
Copyright Statement
© 2025 Published by Elsevier Ltd. Thisis an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).
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Publication Status
Published
Article Number
101988
Date Publish Online
2025-09-18