Development of yttrium-containing self-passivating tungsten alloys for future fusion power plants

Wegener, T.; Klein, F.; Litnovsky, A.; Rasiński, M.; Brinkmann, J.; Koch, F.; Linsmeier, Ch.

doi:10.1016/j.nme.2016.07.011

Cited by 62 publications

(36 citation statements)

References 15 publications

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“…Thus, the calculation agrees with the results from EDX. Previously [16] it is presented that effective passivation requires around 0.6 wt. % of Y and more than 8 wt.…”

Section: How Long Can the Materials Last?mentioning

confidence: 99%

“…Thus, a W-12Cr-0.6Y alloy is oxidized in a dedicated experiment, consisting of two parts: part 1 starts with 65 min oxidation at 1273 K in natural O 2 Figure 5. In the alloy beneath the oxide, the ratio of 16 O/…”

Section: On the Growth Direction Of The Oxidementioning

confidence: 99%

“…Cr is the remaining element capable of forming a protective layer. A small amount of Y is found to be crucial for the improved oxidation resistance [16,23], in comparison to binary W-Cr or W-Cr-Ti alloys, which were investigated in other studies [5].…”

Section: Introductionmentioning

confidence: 97%

“…In the case of a LOCA, W oxidizes to WO 3 and then sublimates [15]. For a typical 1000 m 2 surface of the first wall, several hundreds of kg per week of radioactive W would sublimate at 1273 K, and even more at higher temperatures [16]. This sublimation is severely hazardous for the environment and a major drawback of pure W as an armor material in DEMO.…”

Section: Introductionmentioning

confidence: 99%

“…Previous works on W-Cr-Y alloys featured an elemental composition scan by systematically varying the concentration of Cr and Y. These studies resulted in the optimized alloy composition of W-12Cr-0.6Y [16]. Here and in the following the numbers before the element represent the concentration in weight (wt.)…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

On Oxidation Resistance Mechanisms at 1273 K of Tungsten-Based Alloys Containing Chromium and Yttria

Klein

Wegener

Litnovsky

et al. 2018

Metals

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Tungsten (W) is currently deemed the main candidate for the plasma-facing armor material of the first wall of future fusion reactors, such as DEMO. Advantages of W include a high melting point, high thermal conductivity, low tritium retention, and low erosion yield. However, was an accident to occur, air ingress into the vacuum vessel could occur and the temperature of the first wall could reach 1200 K to 1450 K due to nuclear decay heat. In the absence of cooling, the temperature remains in that range for several weeks. At these temperatures, the radioactive tungsten oxidizes and then volatilizes. Smart W alloys are therefore being developed. Smart alloys are supposed to preserve properties of W during plasma operation while suppressing tungsten oxide formation in case of an accident. This study focuses on investigations of thin film smart alloys produced by magnetron sputtering. These alloys provide an idealistic system with a homogeneous distribution of the elements W, chromium (Cr), and yttrium (Y) on an atomic scale. The recommended composition is W with 12 weight % of Cr and 0.5 weight % of Y. Passivation and a suppression of WO 3 sublimation is shown. For the first time, the mechanisms yielding the improved oxidation resistance are analyzed in detail. A protective Cr 2 O 3 layer forms at the surface. The different stages of the oxidation processes up to the failure of the protective function are analyzed for the first time. Using 18 O as a tracer, it is shown for the first time that the oxide growth occurs at the surface of the protective oxide. The Cr is continuously replenished from the bulk of the sample, including the Cr-rich phase which forms during exposure at 1273 K. A homogenous distribution of yttria within the W-matrix, which is preserved during oxidation, is a peculiarity of the analyzed alloy. Further, an Y-enriched nucleation site is found at the interface between metal and oxide. This nucleation sites are deemed to be crucial for the improved oxidation resistance.

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“…Thus, the calculation agrees with the results from EDX. Previously [16] it is presented that effective passivation requires around 0.6 wt. % of Y and more than 8 wt.…”

Section: How Long Can the Materials Last?mentioning

confidence: 99%

Section: On the Growth Direction Of The Oxidementioning

confidence: 99%

Section: Introductionmentioning

confidence: 97%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

On Oxidation Resistance Mechanisms at 1273 K of Tungsten-Based Alloys Containing Chromium and Yttria

Klein

Wegener

Litnovsky

et al. 2018

Metals

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Fusion Materials Development at Forschungszentrum Jülich

Coenen

2020

Adv Eng Mater

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Material issues pose a significant challenge for the design of future fusion reactors. From a historic point of view, the material mix used for the first wall of a fusion reactor has continually evolved, from original steel vessels to carbon and other low-Z materials such as beryllium to tungsten as the primary candidate for a reactor's first wall armor and divertor material. For materials considered for fusion applications, a highly integrated approach is necessary. Resilience against neutron damage, good power exhaust, and oxidation resistance during accidental air ingress are design relevant issues while deciding on new materials or improving upon baseline materials. Neutron-induced effects, e.g., transmutation adding to embrittlement, retention, and changes to thermomechanical properties, are crucial to material performance. In this contribution, the recent progress (2013-2019) in fusion materials development for current and future fusion devices, at Forschungszentrum Jülich GmbH, with activities focussing on advanced materials and their characterization is given. It is a continuation and extension of the work given by Coenen et al.

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Monte Carlo simulations of pure tungsten and advanced “smart” tungsten alloys under helium bombardment for future fusion power plants

Laaziz

Asmae

Fechtal

et al. 2021

Surface & Interface Analysis

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Development of yttrium-containing self-passivating tungsten alloys for future fusion power plants

Cited by 62 publications

References 15 publications

On Oxidation Resistance Mechanisms at 1273 K of Tungsten-Based Alloys Containing Chromium and Yttria

On Oxidation Resistance Mechanisms at 1273 K of Tungsten-Based Alloys Containing Chromium and Yttria

Fusion Materials Development at Forschungszentrum Jülich

Monte Carlo simulations of pure tungsten and advanced “smart” tungsten alloys under helium bombardment for future fusion power plants

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