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| Naji, M. |
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| Motta, Antonella |
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| Aletan, Dirar |
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| Mohamed, Tarek |
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| Ertürk, Emre |
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| Taccardi, Nicola |
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| Kononenko, Denys |
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| Petrov, R. H. | Madrid |
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| Alshaaer, Mazen | Brussels |
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| Bih, L. |
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| Casati, R. |
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| Muller, Hermance |
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| Kočí, Jan | Prague |
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| Šuljagić, Marija |
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| Kalteremidou, Kalliopi-Artemi | Brussels |
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| Azam, Siraj |
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| Ospanova, Alyiya |
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| Blanpain, Bart |
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| Ali, M. A. |
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| Popa, V. |
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| Rančić, M. |
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| Ollier, Nadège |
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| Azevedo, Nuno Monteiro |
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| Landes, Michael |
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| Rignanese, Gian-Marco |
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Bonnekoh, Carsten
in Cooperation with on an Cooperation-Score of 37%
Topics
Publications (13/13 displayed)
- 2024Additive manufacturing of novel complex tungsten components via electron beam melting: Basic properties and evaluation of the high heat flux behavior
- 2024Hydrogen diffusion and trapping in a cryogenic processed high-Cr ferrous alloy
- 2024Tungsten alloys R&D program at KIT
- 2022Effect of neutron irradiation on ductility of tungsten foils developed for tungsten-copper laminates
- 2022Effect of neutron irradiation on ductility of tungsten foils developed for tungsten-copper laminatescitations
- 2021Der Spröd-duktil-Übergang in ultrafeinkörnigem Wolfram
- 2021Technological Processes for Steel Applications in Nuclear Fusion
- 2020Elucidating the microstructure of tungsten composite materials produced by powder injection molding
- 2020The brittle-to-ductile transition in cold-rolled tungsten sheets: the rate-limiting mechanism of plasticity controlling the BDT in ultrafine-grained tungstencitations
- 2020The brittle-to-ductile transition in cold-rolled tungsten sheets: On the loss of room-temperature ductility after annealing and the phenomenon of 45° embrittlementcitations
- 2020The brittle-to-ductile transition in cold-rolled tungsten sheets: On the loss of room-temperature ductility after annealing and the phenomenon of 45° embrittlementcitations
- 2020The brittle-to-ductile transition in cold-rolled tungsten sheets: Contributions of grain and subgrain boundaries to the enhanced ductility after pre-deformation
- 2017Reducing the brittle-to-ductile transition temperature of tungsten to − 50 °C by cold rolling
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article
The brittle-to-ductile transition in cold-rolled tungsten sheets: On the loss of room-temperature ductility after annealing and the phenomenon of 45° embrittlement
Abstract
The high brittle-to-ductile transition (BDT) temperature of conventionally produced tungsten (W), challenges the design of W-based structural components. Recent studies have demonstrated the potential of cold rolling to produce W sheets, which are ductile at room temperature and exhibit a BDT temperature of 208 K. In order to assess the thermal stability of these materials, we conducted isothermal heat treatments (at 1300 K, for annealing durations between 0.1 h and 210 h) combined with studies on the evolution of mechanical properties and microstructure of a severely deformed undoped W sheet. With this work, we demonstrate the need for a stabilized microstructure before utilization of cold-rolled W in high-temperature applications can take place successfully. After annealing at 1300 K for 6 h, the material properties changed remarkably: The BDT temperature increases from 208 K to 473 K and the sharp BDT of the as-rolled condition transforms into a wide transition regime spanning over more than 200 K. This means in fact, an endangered structural integrity at room temperature. We also address the so-called phenomenon of 45° embrittlement of W sheets. Here we show that cleavage fracture in strongly textured W sheets always takes place with an inclination angle of 45° to the rolling direction, independent of the studied material condition, whether as-rolled or annealed. An in-depth study of the microstructure indicates a correlation between an increased BDT temperature caused by annealing and microstructural coarsening presumably by extended recovery. We conclude that 45° embrittlement needs to be comprehended as a combined effect of an increased spacing between grain boundaries along the crack front, leading to an increased BDT, and a high orientation density of the rotated cube component or texture components close to that, which determine the preferred crack propagation of 45° to the rolling direction.