Journals

Showing 1 - 10 of 55 Journals Results
2020
UKAEA-CCFE-PR(20)125

The vacancies produced in high energy collision cascades of irradiated tungsten can form vacancy clusters or prismatic vacancy dislocation loops. Moreover, vacancy loops can easily transform into planar vacancy clusters. We investigated the formation energies of these three types of vacancy …

Preprint Published
2020
UKAEA-CCFE-PR(20)107

One of the key challenges for the development of high-performance fusion materials is to design materials capable of maintaining mechanical and structural integrity under the extreme levels of displacement damage, high temperature and transmutation rates. High-entropy alloys (HEAs) and other concentrated alloys have attracted attention with regards…

Preprint
2020
UKAEA-CCFE-PR(20)106

The development of High-Entropy Alloys (HEAs) focuses on exploring compositional regions in multicomponent systems with all alloy elements in equal or near-equal atomic concentrations. Initially it was based on the main idea that high mixing configurational entropy contributions to the alloy free energy could promote the formation of a single solid…

Preprint Purchase
2020
UKAEA-CCFE-PR(20)79

Point defects in body-centred cubic Fe, Cr and concentrated random magnetic Fe-Cr are investigated using density functional theory and theory of elasticity. The volume of a substitutional Cr atom in ferromagnetic bcc Fe is approximately 18% larger than the…

Preprint
2020
UKAEA-CCFE-PR(20)78

During an accident with loss-of-coolant and air ingress in DEMO, the temperature of tungsten first wall cladding may exceed 1000oC and remain for months leading to tungsten oxidation. The radioactive tungsten oxide can be mobilized to the environment at rates of 10 – 150 kg per hour. Smart tungsten-based alloys are under development to…

Preprint Purchase
2019
UKAEA-CCFE-PR(19)44

The low energy structures of irradiation-induced defects have been studied in detail, as these determine the available modes by which a defect can diffuse or relax. As a result, there are many studies concerning the relative energies of possible defect structures, and empirical potentials are commonly fitted to or evaluated with respect to these en…

Preprint Published
2019
UKAEA-CCFE-PR(19)42

High temperature, neutron irradiated single crystal tungsten, with a post irradiation composition of W-1.20±0.11at.%Re-0.11±0.05at.%Os-0.03±0.01at.%Ta was characterised using a combination of Atom Probe Tomography (APT) and Scanning Transmission Electron Microscopy (STEM). APT showed that within nanoscale clusters of Re/Os, the atomic density wa…

Preprint Purchase
2019
UKAEA-CCFE-PR(19)38

Multi-component alloy Fe-Cr-Mn-Ni is a promising new candidate system not only because of its potential application as structural materials beyond conventional austenitic steels but also for fundamental physics role played by Mn element in Fe-Cr-Ni based alloys. In this work, the phase stability of magnetic face-centered cubic (fcc) Fe-Cr-Mn-Ni sys…

Preprint
2019
UKAEA-CCFE-PR(19)37

The diffusion of defects in crystalline materials governs macroscopic behaviour in a wide range of processes, including alloying, precipitation, phase transformation, and creep. In real materials, intrinsic defects are unavoidably bound to static trapping centres such as impurity atoms, meaning that their diffusion is controlled by the de-trapping …

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The published version of this paper is currently under embargo and will be available on 27/01/2021
2019
UKAEA-CCFE-PR(19)22

A viable fusion power station is reliant on the development of plasma facing materials that can withstand the combined effects of high temperature operation and high neutron doses. In this study we focus on W, the most promising candidate material. Re is the primary transmutation product and has been shown to induce embrittlement through cluster fo…

Preprint Published