Evolution of carbon and oxygen concentration in tungsten prepared by field assisted sintering and its effect on ductility

Veverka, Jakub; Vilémová, Monika; Chlup, Zdeněk; Hadraba, Hynek; Lukáč, František; Csáki, Štefan; Matějíček, Jiří; Vontorová, Jiřina; Chráska, Tomáš

doi:10.1016/j.ijrmhm.2021.105499

Cited by 9 publications

(5 citation statements)

References 39 publications

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“…As shown in this work and previous research 39 , 40 , oxygen impurities present a consistent challenge in both types of SPS-fabricated W composites. In the W-Zr precursors, the presence of zirconium oxide in the sample potentially limits the dissolution of Zr placeholders, which is essential for producing porous W. In the DSW composites, the oxidation of carbide dispersoids significantly reduces the material′s thermal conductivity.…”

Section: Discussionsupporting

confidence: 84%

Discovering tungsten-based composites as plasma facing materials for future high-duty cycle nuclear fusion reactors

Marchhart,

Hargrove,

Marin

et al. 2024

Sci Rep

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Despite of excellent thermal properties and high sputtering resistance, pure tungsten cannot fully satisfy the requirements for plasma facing materials in future high-duty cycle nuclear fusion reactions due to the coupled extreme environments, including the high thermal loads, plasma exposure, and radiation damage. Here, we demonstrated that tungsten-based composite materials fabricated using spark-plasma sintering (SPS) present promising solutions to these challenges. Through the examination of two model systems, i.e., tungsten-zirconium composite for producing porous tungsten near the surface and dispersoid-strengthened tungsten, we discussed both the strengths and limitations of the SPS-fabricated materials. Our findings point towards the need for future studies aimed at optimizing the SPS process to achieve desired microstructures and effective control of oxygen impurities in the tungsten-based composite materials.

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Section: Discussionsupporting

confidence: 84%

Discovering tungsten-based composites as plasma facing materials for future high-duty cycle nuclear fusion reactors

Marchhart,

Hargrove,

Marin

et al. 2024

Sci Rep

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“…For the presented experiment, structural steel marked Kosmalt E300T (U. S. Steel Košice, s.r.o., Košice, Slovak Republic) was chosen. Its chemical composition was determined using a Spectruma Analytik GMBH (Hof, Bayern, Germany) glow discharge Coatings 2024, 14, 493 3 of 15 optical emission spectrometer (model GDA 750) under excitation conditions of 700 V and 35 mA [27][28][29] and elemental analysis (Eltra CS 2000) (Haan, Germany) [30,31] (elements marked *) and is shown in Table 1. The pictures (Figure 2) show the microstructure of this steel.…”

Section: Methodsmentioning

confidence: 99%

Quality of Zinc Coating Formed on Structural Steel by Hot-Dip Galvanizing after Surface Contamination

Vontorová,

Mohyla,

Kreislová

2024

Coatings

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This paper deals with the evaluation of the surface of structural steel whose samples were deliberately contaminated with transparent spray primer, adhesive label glue, and welding sprays prior to hot-dip galvanizing. The galvanized samples were studied by optical microscopy, GDOES, adhesion tests, and condensation humidity tests. The effect of surface contamination on the quality of the zinc coating was found to be significant. In some cases, the zinc coating is damaged (after contamination with welding sprays), in others, it is completely absent (after contamination with spray primer or adhesive label glue).

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Section: Design Principles and Sintering Practicesmentioning

confidence: 99%

“…One of the most concerning impurities for refractory metals is oxygen, which is difficult to be fully removed and may cause problems in densification, processing, properties (e.g., embrittlement), and service. [83][84][85][86] On the forming side, high compacting pressure is known to help improve powder packing and homogenize pore structure. Johnson [33] pressed W powders (with a BET particle size of 0.11 µm) at 2.7 GPa to a relative density ρ of 77%, which offers high sinterability to reach ρ = 95% and G avg = 0.80 µm when sintered at 1100 °C for 1 h. In this regard, ultra-high-pressure cold isostatic press up to several GPa [87] should work better by offering isotropic stress (which is important for nanopowders that can be easily jammed) and a more uniform microstructure in the powder compacts.…”

Section: General Considerations For Nano Powder Sinteringmentioning

confidence: 99%

Powder Metallurgy Route to Ultrafine‐Grained Refractory Metals

Zhang

et al. 2023

Advanced Materials

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Ultrafine‐grained (UFG) refractory metals are promising materials for applications in aerospace, microelectronics, nuclear energy, and many others under extreme environments. Powder metallurgy (PM) allows to produce such materials with well‐controlled chemistry and microstructure at multiple length scales and near‐net shape manufacturing. However, sintering refractory metals to full density while maintaining a fine microstructure is still challenging due to the high sintering temperature and the difficulty to separate the kinetics of densification versus grain growth. Here an overview of the sintering issues, microstructural design rules, and PM practices towards UFG and nanocrystalline refractory metals are sought to be provided. The previous efforts shall be reviewed to address the processing challenges, including the use of fine/nanopowders, second‐phase grain growth inhibitors, and field‐assisted sintering techniques. Recently, pressureless two‐step sintering has been successfully demonstrated in producing dense UFG refractory metals down to ≈300 nm average grain size with a uniform microstructure and this technological breakthrough shall be reviewed. PM progresses in specific materials systems shall be next reviewed, including elementary metals (W and Mo), refractory alloys (W‐Re), refractory high‐entropy alloys, and their composites. Last, future developments and the endeavor towards UFG and nanocrystalline refractory metals with exceptionally uniform microstructure and improved properties are outlined.

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Evolution of carbon and oxygen concentration in tungsten prepared by field assisted sintering and its effect on ductility

Cited by 9 publications

References 39 publications

Discovering tungsten-based composites as plasma facing materials for future high-duty cycle nuclear fusion reactors

Discovering tungsten-based composites as plasma facing materials for future high-duty cycle nuclear fusion reactors

Quality of Zinc Coating Formed on Structural Steel by Hot-Dip Galvanizing after Surface Contamination

Powder Metallurgy Route to Ultrafine‐Grained Refractory Metals

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