This title appears in the Scientific Report :
2017
Please use the identifier:
http://dx.doi.org/10.1016/j.fusengdes.2017.03.072 in citations.
Please use the identifier: http://hdl.handle.net/2128/15784 in citations.
Development and analyses of self-passivating tungsten alloys for DEMO accidental conditions
Development and analyses of self-passivating tungsten alloys for DEMO accidental conditions
Tungsten is considered the main candidate material for the first-wall in DEMO due to its high melting point, low erosion yield and low tritium retention. Nevertheless, it can cause a substantial safety issue in a loss-of-coolant accident (LOCA) in combination with air ingress into the plasma vessel,...
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Personal Name(s): | Wegener, Tobias (Corresponding author) |
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Klein, Felix / Litnovsky, Andrey / Rasinski, Marcin / Brinkmann, Jens / Koch, Freimut / Linsmeier, Christian | |
Contributing Institute: |
Plasmaphysik; IEK-4 |
Published in: | Fusion engineering and design, 124 (2017) S. 183-186 |
Imprint: |
New York, NY [u.a.]
Elsevier
2017
|
DOI: |
10.1016/j.fusengdes.2017.03.072 |
Document Type: |
Journal Article |
Research Program: |
Helmholtz Interdisciplinary Doctoral Training in Energy and Climate Research (HITEC) Methods and Concepts for Material Development |
Link: |
OpenAccess OpenAccess |
Publikationsportal JuSER |
Please use the identifier: http://hdl.handle.net/2128/15784 in citations.
Tungsten is considered the main candidate material for the first-wall in DEMO due to its high melting point, low erosion yield and low tritium retention. Nevertheless, it can cause a substantial safety issue in a loss-of-coolant accident (LOCA) in combination with air ingress into the plasma vessel, due to the formation and sublimation of volatile neutron activated tungsten oxide. Self-passivating tungsten alloys introduce a passive safety mechanism by forming a stable chromic oxide scale on the surface acting as a diffusion barrier for oxygen and preventing the formation of tungsten oxide. Self-passivating tungsten alloys optimized for oxidation resistance containing ∼12 wt.% Cr and ∼0.6 wt.% Y are investigated under conditions of argon–oxygen, humid argon and humid air atmospheres at different partial pressures and temperatures ranging from 1073 to 1273 K. Thin films with ∼3.5 μm thickness produced by magnetron sputter deposition are used as a model system. The oxidation resistance of these films in an argon–20 vol.% oxygen atmosphere is sufficient to prevent formation and release of tungsten oxide at temperatures of from 1073 to 1273 K. The sublimation of Cr in nitrogen–oxygen–water atmosphere at T ≥ 1273 K is discussed. A deeper understanding of the governing processes for oxygen/Cr diffusion under different atmospheres is gained, supported by SEM/EDX in combination with FIB cross-section and TGA measurements. |