Daniel Mason Andrea Sand Sergei Dudarev
We describe the development of a new object kinetic Monte Carlo code where the elementary defect objects are off-lattice atomistic configurations. Atomic-level transitions are used to transform and translate objects, to split objects and to merge them together. This gradually constructs a database of atomic configurations- a set of relevant defect …
Preprint PublishedPui-Wai Ma S. L. Dudarev
Vacancy formation and migration control self-diffusion in pure crystalline materials, whereas irradiation produces high concentrations of vacancy and self-interstitial atom defects, exceeding by many orders of magnitude the thermal equilibrium concentrations. The defects themselves, and the extended dislocation microstructure formed under irradi…
Preprint PublishedM. R. Gilbert J.-Ch. Sublet
Nuclear inventory simulations have a vital role to play in the planning and execution of future fusion experiments and power plants. They are able to predict the transmutation (burn-up) response of material compositions under neutron irradiation, thus providing information about the build-up of impurities that could impact on material performanc…
Preprint PublishedPui-Wai Ma S. L. Dudarev
For several decades, the striking contradiction between the Huang diffuse scattering experiments, resistivity recovery data, and predictions derived from density functional theory (DFT) remained one of the mysteries of defect physics in molybdenum. Since the nineteen seventies, observations of Huang X-ray diffuse scattering appeared to indicate …
Preprint PublishedChris Hardie Andrew J. London Joven J. H. Lim Rob Bamber Tonci Tadic Marin Vuksic Stjepko Fazinic
The effects of radiation damage on materials are strongly dependant on temperature, making it arguably the most significant parameter of concern in nuclear engineering. Owing to the challenges and expense of irradiating and testing materials, material property data is often limited to few irradiation conditions and material variants. A new techniqu…
Preprint PublishedA. Fernandez-Caballero M. Fedorov J.S. Wrobel P.M. Mummery D. Nguyen
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 PublishedO. El-Atwani N. Li M. Li A. Devaraj M. Schneider D. Sobieraj J.S. Wrobel D. Nguyen-Manh S. A. Maloy E. Martinez
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 PublishedLeo Ma S. L. Dudarev
Formation and migration energies, elastic dipole and relaxation volume tensors of nano-defects are the parameters that determine the rates of evolution of microstructure under irradiation and the magnitude of macroscopic elastic stresses and strains resulting from the accumulation of defects in materials. To find accurate values of these parameters…
Preprint PublishedV. Kuksenko S. Roberts E. Tarleton
Four industrial beryllium grades were tested via nanoindentation. An extremely high variation of hardness was observed in all samples. Analysis of the nanoindentation data in combination with SEM/EBSD measurements demonstrated that the crystallographic orientation of the indented grain was the major source of the wide variation in hardness, which w…
Preprint PublishedS. L. Dudarev D. R. Mason E. Tarleton P.-W. Ma A. E. Sand
Predicting strains, stresses and swelling in power plant components exposed to irradiation directly from the observed or computed defect and dislocation microstructure is a fundamental problem of fusion power plant design that has so far eluded a practical solution. We develop a model, free from parameters not accessible to direct evaluation or obs…
Preprint Published