| 1. |
- Bonny, G., et al.
(författare)
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Density functional theory-based cluster expansion to simulate thermal annealing in FeCrW alloys
- 2017
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Ingår i: Philosophical Magazine. - : Taylor & Francis. - 1478-6435 .- 1478-6443. ; 97:5, s. 299-317
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Tidskriftsartikel (refereegranskat)abstract
- In this work, we develop a rigid lattice cluster expansion as an ultimate goal to track the micro-structural evolution of Eurofer steel under neutron irradiation. The fact that all (defect) structures are mapped upon a rigid lattice allows a simplified computation and fitting procedure, thus enabling alloys of large chemical complexity to be modelled. As a first step towards the chemical complexity of Eurofer steels, we develop a cluster expansion (CE) for the FeCrW-vacancy system based on density functional theory (DFT) calculations in the dilute alloy limit. The DFT calculations suggest that only CrW clusters containing vacancies are stabilised. The cluster expansion was used to simulate thermal annealing in Fe–20Cr–xW alloys at 773 K. It is found that the addition of W to the alloy results in a non-linear decrease in the precipitation kinetics. The CE was found suitable to describe the energetics of the FeCrW-vacancy system in the Fe-rich limit.
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| 2. |
- Castin, N., et al.
(författare)
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Advanced atomistic models for radiation damage in Fe-based alloys : Contributions and future perspectives from artificial neural networks
- 2018
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Ingår i: Computational materials science. - : Elsevier. - 0927-0256 .- 1879-0801. ; 148, s. 116-130
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Tidskriftsartikel (refereegranskat)abstract
- Machine learning, and more specifically artificial neural networks (ANN), are powerful and flexible numerical tools that can lead to significant improvements in many materials modelling techniques. This paper provides a review of the efforts made so far to describe the effects of irradiation in Fe-based and W-based alloys, in a multiscale modelling framework. ANN were successfully used as innovative parametrization tools in these models, thereby greatly enhancing their physical accuracy and capability to accomplish increasingly challenging goals. In the provided examples, the main goal of ANN is to predict how the chemical complexity of local atomic configurations, and/or specific strain fields, influence the activation energy of selected thermally-activated events. This is most often a more efficient approach with respect to previous computationally heavy methods. In a future perspective, similar schemes can be potentially used to calculate other quantities than activation energies. They can thus transfer atomic-scale properties to higher-scale simulations, providing a proper bridging across scales, and hence contributing to the achievement of accurate and reliable multiscale models.
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| 3. |
- Pascuet, M. I., et al.
(författare)
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Electrical Response to Mechanical Deformations in Cr-SiOx Cermet Thin Films (Respuesta Eléctrica a las Deformaciones Mecánicas en Películas Delgadas del Cermet Cr-SiOx)
- 1996
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Ingår i: Anales AFA. ; 7:1, s. 137-140
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Tidskriftsartikel (refereegranskat)abstract
- Electrical properties and strain gauge factor of Cr/SiOx cermet films with compositions 50/50 and 70/30 wt% were investigated in order to evaluate their use in strain gauge devices. The films were deposited by flash evaporation. The microstructures and resulting phases were characterized by electron diffraction and electron microscopy. The influence of the thickness and deposition rate on the sheet resistance, the temperature coefficient of resistance and the gauge factor were investigated. The results are consistent with a mixed conduction mechanism with metallic and a thermally activated tunneling components, between interconnected and discrete conductive phases, respectively.
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