UKAEA Journals

Showing 1 - 10 of 18 Journals Results
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 so…

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 volume of a host Fe atom, whereas the volume of a substitutional Fe atom in antiferromagnetic…

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 develop…

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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 Published
2018
UKAEA-CCFE-PR(18)84

Configuration entropy is believed to stabilize disordered solid solution phases in multicomponent systems at elevated temperatures over intermetallic compounds by lowering the Gibbs free energy. Traditionally the …

Preprint Published
2018
UKAEA-CCFE-PR(18)77

A novel W-based refractory high entropy alloy with outstanding radiation resistance has been developed. The alloy was grown as thin films showing a bimodal grain size distribution in the nanocrystalline and ultrafine regimes and a unique 4 nm lamella-like structure revealed by atom probe tomography (APT). Transmission electron microscopy (TEM) and …

Preprint Published
2017

The structural and magnetic properties of CoCrFeyNi and CoCrFeNi-Pdx alloys earlier investigated experimentally by x-ray and neutron diffraction techniques and magnetometry have been theoretically reproduced using two complementary approaches for electronic structure calculations, i.e. the Korringa–Kohn–Rostoker method with the coherent potenti…

Published
2017
CCFE-PR(17)55

High Entropy Alloys (HEAs) is a fascinating field of research, with an increasing number of new alloys discovered. This would hardly be conceivable without the aid of materials modeling and the computational alloy design to investigate the immense compositional space. The simplicity of the microstructure achieved contrasts with the enormous complex…

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2017
CCFE-PR(17)14

In high-entropy alloys (HEAs), the local chemical fluctuations from disordered solute solution state into segregation, precipitation and ordering configurations are complex due to the large number of elements. In this work, the cluster expansion (CE) Hamiltonian for multi-component alloy systems is developed in order to investigate the dependence o…

Preprint Purchase
2016
CCFE-PR(16)52

Helium is produced in the structural materials of nuclear power plants by the nuclear transmutation following neutron irradiation. Since the solubility of helium in all the metals is extremely low, helium tends to be trapped at defects such as vacancies, dislocations and grain boundaries, which cause materials embrittlement. Density functional the…

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