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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 55 records · Page 3
All sourcesNASA NTRSDOE OSTI
DOE OSTI2022

A compact x-ray diffraction system for dynamic compression experiments on pulsed-power generators

Pulsed-power generators can produce well-controlled continuous ramp compression of condensed matter for high-pressure equation-of-state studies using the magnetic loading technique. X-ray diffraction (XRD) data from dynamically compressed samples provide direct measurements of the elastic compression of the crystal lattice, onset of plastic flow, strength–strain rate dependence, structural phase transitions, and density of crystal defects, such as dislocations. Here, we present a cost-effective, compact, pulsed x-ray source for XRD measurements on pulsed-power-driven ramp-loaded samples. This combination of magnetically driven ramp compression of materials with a single, short-pulse XRD diagnostic will be a powerful capability for the dynamic materials’ community to investigate in situ dynamic phase transitions critical to equation of states. Finally, we present results using this new diagnostic to evaluate lattice compression in Zr and Al and to capture signatures of phase transitions in CdS.

47 OTHER INSTRUMENTATION↗
DOE OSTI2025

Statistical evaluation of microscale stress conditions leading to void nucleation in the weak shock regime

Here, we investigate the heterogeneity of the stress state driven by anisotropic deformation response at the single crystal level through five statistical volume element (SVE) calculations of polycrystalline BCC tantalum. This work focuses on grain boundaries as a prominent material defect type prone to void nucleation based upon experimental observations of predominantly intergranular void nucleation in this material. The SVEs are constructed to be statistically representative of larger volumes of material and are meshed such that mean and standard deviation of grain size and orientation information is reconstructed. The computational meshes feature hexahedral (brick) elements and smooth conformal grain boundaries where significant stress concentration is known to occur, a tail effect of interest in the extreme events process of dynamic ductile damage. An existing micromechanical crystallographic plasticity model shown to capture the single crystal behavior of BCC tantalum well is used to perform the polycrystal calculations. The model includes representation of the non-Schmid effect of non-planar screw dislocation kinetics in tantalum. A three-dimensional stress state time profile predicted by damage modeling of a flyer plate impact experiment is applied as boundary conditions to each SVE. Resulting grain boundary stress state statistics are strongly non-Gaussian. Significant structural evolution is observed within the compressive hold before unloading into tension in the stress profile. Strong angular dependence of grain boundary traction magnitude with shock direction is observed. Non-Schmid effects continue to suggest their influence on propensity of microstructural defect types to nucleate voids. A general void nucleation criterion is proposed using probability theory. The general framework is specified to polycrystalline BCC tantalum in the weak shock regime to include the SVE calculations and literature molecular dynamics calculations of grain boundary void nucleation strength. Probability density functions (PDFs) are used to describe the interaction between the local stress state heterogeneity and the distributed grain boundary void nucleation strength state. A causation entropy maximization procedure removes the requirement for ad hoc selection of a PDF functional form and provides a rigorous procedure for data-based PDF determination. The resulting physically informed PDF describes the spatial appearance frequency of nucleated voids as a function of applied macroscale pressure. Lower length scale physics are thus packaged in a precise and computationally efficient way to provide computational plasticity insight to macroscale dynamic ductile damage models.

36 MATERIALS SCIENCE↗
DOE OSTI2024

Kink bands promote exceptional fracture resistance in a NbTaTiHf refractory medium-entropy alloy

Single-phase body-centered cubic (bcc) refractory medium- or high-entropy alloys can retain compressive strength at elevated temperatures but suffer from extremely low tensile ductility and fracture toughness. We examined the strength and fracture toughness of a bcc refractory alloy, NbTaTiHf, from 77 to 1473 kelvin. This alloy’s behavior differed from that of comparable systems by having fracture toughness over 253 MPa·m 1/2 , which we attribute to a dynamic competition between screw and edge dislocations in controlling the plasticity at a crack tip. Whereas the glide and intersection of screw and mixed dislocations promotes strain hardening controlling uniform deformation, the coordinated slip of <111> edge dislocations with {110} and {112} glide planes prolongs nonuniform strain through formation of kink bands. These bands suppress strain hardening by reorienting microscale bands of the crystal along directions of higher resolved shear stress and continually nucleate to accommodate localized strain and distribute damage away from a crack tip.

36 MATERIALS SCIENCE↗
DOE OSTI2019

Validation of Puncture Simulations with Various Probe Geometries

Ductile materials fail through mechanisms of void nucleation and coalescence. A tensile test of a ductile metal begins with reversible elastic deformation, proceeds through permanent plastic deformation, and ends with rupture. Dislocations in the grains of a metal do not slip in the elastic range but begin moving in the plastic range. As the dislocations interact with grain boundaries and each other, they cause increasing resistance to plastic deformation, termed work hardening. The applied load and the true stress rise together during this process. When the dislocations have no room to move, voids open up in the material. As these voids coalesce into cracks, the true stress rises rapidly and the sustained load decreases. Rupture occurs when the cracks propagate through the specimen and it loses all load-carrying capacity. The complexity of the ductile fracture phenomenon continues to attract substantial attention from researchers. Sharp objects in a production environment can puncture fragile components made from ductile metals. Non-linear dynamic simulations help engineers to plan processes such that these components do not fail when an accident happens. The projectile is termed a probe, and the component is the target. The surface of the probe that contacts the target may be sharp, blunt, or flat. Probes are typically cylindrical for simplicity, but other shapes that exist in the production environment are equally applicable.

36 MATERIALS SCIENCE↗
DOE OSTI2016

Report on fundamental modeling of irradiation-induced swelling and creep in FeCrAl alloys

In order to improve the accident tolerance of light water reactor (LWR) fuel, alternative cladding materials have been proposed to replace zirconium (Zr)-based alloys. Of these materials, there is a particular focus on iron-chromium-aluminum (FeCrAl) alloys due to much slower oxidation kinetics in high-temperature steam than Zr-alloys. This should decrease the energy release due to oxidation and allow the cladding to remain integral longer in the presence of high temperature steam, making accident mitigation more likely. As a continuation of the development for these alloys, the material response must be demonstrated to provide suitable radiation stability, in order to ensure that there will not be significant dimensional changes (e.g., swelling), as well as quantifying the radiation hardening and radiation creep behavior. In this report, we describe the use of cluster dynamics modeling to evaluate the defect physics and damage accumulation behavior of FeCrAl alloys subjected to neutron irradiation, with a particular focus on irradiation-induced swelling and defect fluxes to dislocations that are required to model irradiation creep behavior.

36 MATERIALS SCIENCE↗
DOE OSTI2019

Modeling and Simulation of Microstructure Evolution and Deformation in an Irradiated Environment

The ability to predict the behavior of structural components in a nuclear power plant is critical to the nuclear industry. Structural metals in the primary loop of nuclear power plants must endure challenges such as irradiation and mechanical and thermal loading, and these structural metal components must continue to function in potential transient and accident conditions throughout the operational lifetime of the power plant. This extreme operational environment changes the metal microstructure by creating additional defects. The physical interactions of dislocations with these defects govern how the metal will respond to future conditions. Therefore predicting the mechanical response of these metals requires a set of physically based and reliable models of dislocation and defect interactions. These microstructure elements include glide mobile and immobile dislocations, geometrically necessary dislocations, twinning dislocations, irradiation defects, and thermal aging defects. We present here a continuum dislocation dynamics crystal plasticity framework to capture the interaction mechanisms of these dislocations and defects, verified with a combination of benchmark problems and comparisons with experimental data for two different types of structural metals: alpha iron and nickel-based alloys. In our simulations of $\alpha$ iron we highlight the advantages of applying a Monte Carlo stochastic model of cross slip dislocation motion and show the importance of capturing the 3D nature of glide dislocation and self-interstitial atom loop radiation defect interactions. We demonstrate coupling of glide dislocations with geometrically necessary dislocations to capture the influence of lattice bending, including the sensitivity of the geometrically necessary dislocations to changes in the grain boundary angle. We further examine the interaction of glide dislocations with the twin dislocations and thermally aged defects which have been observed in a nickel-based alloy with additional models. Finally we assess the reliability of this crystal plasticity framework by comparing two dislocation glide velocity models across the range of normal operation temperatures. In successfully applying our crystal plasticity framework to multiple metals, we provide further evidence of the reliability of our approach. The results of this mechanism-based continuum dislocation dynamics crystal plasticity framework can be used to inform engineering scale models throughout the nuclear industry.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Dislocation-graphene interactions in Cu/graphene composites and the effect of boundary conditions: a molecular dynamics study

Here, in this paper, systematic molecular dynamics simulations were employed to study dislocation-graphene interactions in Cu/graphene systems using two carefully selected configurations: (i) edge dislocations in the pileup interacting with graphene during nanoindentation and (ii) complex dislocations interacting with graphene in compression of layered nanopillars. The intrinsic and extrinsic size effects were investigated with respect to varying the Cu lamella thickness and pillar sizes, revealing an anomalous extrinsic size effect: the smaller, the weaker. To understand which boundary conditions are physically consistent, both free and periodic graphene were considered. It was seen that edge dislocations in the pileup continuously transmitted across the free graphene through Cu/graphene interfacial sliding and graphene reorientation, whereas transmission was very difficult for periodic graphene as its in-plane deformation was required. In compression of Cu/graphene nanopillars, the strengthening effect of free graphene was found to be less obvious than that of the periodic case, which could be attributed to free graphene edges acting as dislocation sources after the compressed Cu overflowed the graphene sheet from all directions. We therefore conclude that the strengthening effect of periodic graphene inclusions appears to be overestimated, such that free graphene should be more appropriate.

36 MATERIALS SCIENCE↗
DOE OSTI2014

Energy Frontier Research Center Center for Materials Science of Nuclear Fuels

Scientific Successes • The first phonon density of states (PDOS) measurements for UO2 to include anharmonicity were obtained using time-of-flight inelastic neutron scattering at the Spallation Neutron Source (SNS), and an innovative, experimental-based anharmonic smoothing technique has enabled quantitative benchmarking of ab initio PDOS simulations. • Direct comparison between anharmonicity-smoothed ab initio PDOS simulations for UO2 and experimental measurements has demonstrated the need for improved understanding of UO2 at the level of phonon dispersion, and, further, that advanced lattice dynamics simulations including finite temperatures approaches will be required for handling this strongly correlated nuclear fuel. • PDOS measurements performed on polycrystalline samples have identified the phonon branches and energy ranges most highly impacted by fission-product and hyper-stoichiometry lattice defects in UO2. These measurements have revealed the broad-spectrum impact of oxygen hyper-stoichiometry on thermal transport. The reduction in thermal conductivity caused by hyper-stoichiometry is many times stronger than that caused by substitutional fission-product impurities. • Laser-based thermo-reflectance measurements on UO2 samples irradiated with light (i.e. He) ions to introduce point defects have been coupled with MD simulations and lattice parameter measurements to determine the role of uranium and oxygen point defects in reducing thermal conductivity. • A rigorous perturbation theory treatment of phonon lifetimes in UO2 based on a 3D discretization of the Brillouin zone coupled with experimentally measured phonon dispersion has been implemented that produces improved predictions of the temperature dependent thermal conductivity. • Atom probe investigations of the influence of grain boundary structure on the segregation behavior of Kr in UO2 have shown that smaller amounts of Kr are present at low angle grain boundaries than at large angle grain boundaries due to the more dense dislocation arrays associated with large angle boundaries; this observation has potentially important ramifications for thermal transport in the high burn-up rim region of light water reactor fuel. • A variable charge interatomic potential has been developed that not only provides an accurate representation of the fluorite UO2 phase, it is further capable of describing continuous stoichiometry changes from UO2 to hyper-stoichiometric UO2+x, to U4O9 and U3O7, and possibly to orthorhombic U3O8. This is the first potential that features many-body effects in all possible interactions (U-U, U-O and O-O) combined with the variable charge. • A theoretical proof has been formulated showing that it is necessary to use the so-called model C phase field approach, consisting of Cahn-Hilliard and Allen-Cahn equations, to describe void evolution in irradiated materials. This work resolved a longstanding literature controversy regarding how to model voids at the mesoscale. • A novel cluster dynamics model has been developed for the nucleation of voids and loops in UO2 under irradiation. This model is important in understanding the defect state of UO2 after irradiation and, more importantly, reveals off-stoichiometric states of irradiated UO2 that are critical for understanding the impact of irradiation on thermal transport. Personnel Successes

36 MATERIALS SCIENCE↗
DOE OSTI2016

Mechanical behavior and microstructure of Ti{sub 20}Hf{sub 20}Zr{sub 20}Ta{sub 20}Nb{sub 20} high-entropy alloy loaded under quasi-static and dynamic compression conditions

The microstructure and the mechanical behavior of equimolar Ti{sub 20}Hf{sub 20}Zr{sub 20}Ta{sub 20}Nb{sub 20} high-entropy alloy in a wide range of initial strain rates between ~ 10{sup −3} s{sup −1} and ~ 3.4 × 10{sup 3} s{sup −1} were studied. A significant increment in the yield strength with increasing strain rate was observed. The yield strength at ~ 3.4 × 10{sup 3} s{sup −1} was about 40% higher than that measured at ~ 10{sup −3} s{sup −1}. Analysis by electron backscatter diffraction shows that in the low strain rate regime (up to ~ 10 s{sup −1}) the deformation occurs mainly in evenly distributed bands, while in the dynamic regime the deformation is strongly localized in macroscopic shear bands accompanied by softening even after the onset of yielding. The Kernel Average Misorientation technique reveals a high level of lattice rotation within these bands that also carries intense shear. In addition, X-ray diffraction line profile analysis indicates that the sharp increase in the flow stress is mostly related to an increase of the dislocation density. - Highlights: • Strain rate effect on the plastic behavior of Ti{sub 20}Hf{sub 20}Zr{sub 20}Ta{sub 20}Nb{sub 20} HEA was studied. • Low strain rate regime was characterized by a continuous hardening. • At high strain rates softening occurred shortly after the onset of yielding. • Intense strain localization in shear bands occurred in the high strain rate regime. • High dislocation density explained the upturn of flow stress at high strain rates.

36 MATERIALS SCIENCE↗
DOE OSTI2016

Microstructure, texture, and mechanical properties of friction stir welded commercial brass alloy

Microstructural evolution during friction stir welding of single-phase brass and corresponding mechanical properties were investigated. For this purpose, 2 mm thick brass plate was friction stir welded at a rotational speed of 450 rpm and traverse speed of 100 mm/min. The microstructure of the joint was studied using optical microscopy, scanning electron microscopy equipped with electron back scattered diffraction system, and scanning transmission electron microscopy. The mechanical properties were measured using hardness and tensile tests. The formation of subgrains and their transformation into new grains in conjunction with existence of A{sub 1}{sup ⁎}, A{sub 2}{sup ⁎} and C texture components revealed that the continuous dynamic recrystallization plays a dominant role in the microstructural evolution. However, grain boundary bulging, along with the formation of twin boundaries, and presence of the G texture component showed that the discontinues dynamic recrystallization may participate in the new grain formation. Furthermore, the different strengthening mechanisms, which caused the higher strength of the joint, were discussed. - Highlights: •Microstructural evolution during FSW of a single phase brass was investigated. •CDRX and DDRX were the main mechanisms of the grain structure formation during FSW. •GDRX and SRX were not contributed in grain structure formation. •The lamellas TBs were formed in the SZ of the joints. •Grain boundary, dislocation, and texture effects resulted in higher strength.

36 MATERIALS SCIENCE↗
DOE OSTI2018

Loop-punching suppression induced by growth of helium bubble pair in tungsten

Molecular dynamics and transmission electron microscopy (TEM) are employed to study the formation and evolution of interstitial dislocation loops due to nearby growing helium bubbles. The study reveals a novel mechanism that suppresses further formation of loops. Mass transport of self-interstitial atoms between the bubbles is observed, followed by the loop formation, resulting in a loop- bubble complex in which the Burgers vector may rotate between <100> and 1/2<111>. Such a complex can absorb free loops, effectively influencing the evolution of loop number density. Here, these results provide new understanding of loop-bubble complex formation and saturation of the loop density under a continuous helium implantation in materials.

74 ATOMIC AND MOLECULAR PHYSICS↗
DOE OSTI2017

Multiscale Modeling of Deformation, Fracture and Failure of Fusion Materials and Structures Final Report

The main objective of the research performed at UCLA under grant number DE-FG02-03ER54708 was to develop a physical understanding of the underlying mechanisms that control high-temperature deformation and fracture of fusion structural materials. The key aspect is the synergistic interaction between thermo-mechanical damage phenomena (e.g. creep, fatigue, and fracture), and irradiation damage phenomena (helium and hydrogen bubbles, and irradiation-induced defects). Another thrust area of the research was on the development of constitutive equations for the mechanical behavior of irradiated structures in fusion components (mainly the First Wall and Plasma-Facing components), and in utilizing them in descriptions in large-scale Finite Element Modeling of fusion structures. A parallel experimental effort on thermo-mechanical and plasma-induced damage is designed to validate and confront the developed theoretical and computational predictions. The models have been experimentally validated through experimental tests in simulated plasma transients on specially-designed W samples. This grant started at UCLA on November 14, 2003 and has had successive continuations till November 14, 2017. Research performed under the grant was to develop a range of hierarchical models for the post-elastic deformation, fracture and failure of fusion structural materials. The developed multiscale modeling approach has been based on rigorous mathematical, physical, and computational methods at the forefront of computational materials science. At the fundamental and smallest length scale (nm-μm), we developed advanced rate theory and Monte Carlo approaches to model microstructure evolution, non-equilibrium phase transformations, and dislocation-defect interactions. Microscopic and mesoscopic models of radiation hardening, ductile-to-brittle-transition, post-elastic deformation, plastic instabilities, and fracture processes are based on Dislocation Dynamics (DD) and Grain Growth Dynamics (GGD). At the continuum level, we focused on modeling fracture and failure mechanisms for Virtual Integrated Testing (VISTA), and for understanding the limits of both materials-by-design versus structural component design through advancing the new approach of multiscale-multiphysics. The overall research has been strongly coupled with the U.S. national experimental program to ascertain and verify the range of investigated phenomena. In the following, we give a summary of research progress supported by this grant since its inception till November 14, 2017. Detailed research results are available in our publications, listed in the publications section of this report.

36 MATERIALS SCIENCE↗
DOE OSTI2016

Radiation Enhanced Absorption of Frank Loops by Nanovoids in Cu

Neutron and heavy ion irradiation generally induces voids in metallic materials, and continuous radiations typically result in void swelling and mechanical failure of the irradiated materials. Recent experiments showed that nanovoids in nanotwinned copper could act as sinks for radiation-induced Frank loops, significantly mitigating radiation damage [Y. Chen et al., Nat. Commun. 6:7036 (2015)]. In this paper, we report on structural evolution of Frank loops under cascades and address the role of nanovoids in absorbing Frank loops in detail by using molecular dynamics simulations. Results show that a stand-alone Frank loop is stable under cascades. When Frank loops are adjacent to nanovoids, the diffusion of a group of atoms from the loop into nanovoids is accomplished via the formation and propagation of dislocation loops. The loop-nanovoid interactions result in the shrinkage of the nanovoids and the Frank loops.

36 MATERIALS SCIENCE↗
DOE OSTI2018

Small-Angle Twist Grain Boundaries as Sinks for Point Defects

It is known that grain boundaries (GBs) provide sinks for defects induced into a solid by irradiation. At the same time radiation can change the atomic structure and chemistry of GBs, which in turn impacts the ability of GBs to continue absorbing defects. Although a number of studies have been reported for tilt GBs acting as defect sinks, the questions of how twist GBs evolve to absorb non-equilibrium concentrations of defects and whether GBs saturate as defect sinks for typical irradiation conditions have remained largely unanswered. Here, we used a combination of molecular dynamics and grand canonical Monte Carlo simulations to determine how twist GBs accommodate point defects. We used SiC and {001} and {111} twist GBs as model systems. We found that diffusion of defects along GBs in this material is slow and for most experimentally relevant conditions point defects will accumulate at twist GBs, driving structural and chemical evolution of these interfaces. During irradiation, screw dislocations within GB planes absorb interstitials by developing mixed dislocation segments that climb. Formation of mixed dislocations occurs either by nucleation of interstitial loops or by faulting/unfaulting of stacking faults. Furthermore both types of twist GBs can accommodate a high density of interstitials without losing the crystalline structure, irrespectively of the interstitial flux.

36 MATERIALS SCIENCE↗
DOE OSTI2025

Phase transitions and dimensional cross-over in layered confined solids

The nature of solid phases and cross-over of order–disorder phase transitions from two-dimensional (2D) layers to three-dimensional (3D) bulk in confined atomic systems remain largely unexplained. To this end, we consider noble gases and aluminum confined between graphene sheets at different pressures and temperatures. Using crystal structure search methods and molecular dynamics based on machine-learned potentials with quantum-mechanical accuracy, we identify structures of multilayer confined solids that deviate from simple close packing. Upon heating, we find that confined 2D monolayers melt according to the two-step continuous Kosterlitz–Thouless–Halperin–Nelson–Young theory. However, multilayer solids transition continuously into an intermediate layered-hexatic phase before melting discontinuously into an isotropic liquid. This intermediate phase persists at least up to 12 layers studied here. This change can be qualitatively understood based on the cross-over from 2D topological defects toward 3D ones during melting as the number of layers increases.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2018

Effect of initial orientation on dynamic recrystallization of a zirconium alloy during hot deformation

Highlights: • The dynamic recrystallization process is enhanced by the operation of slip. • Continuous dynamic recrystallization is promoted by the rotation of grains. • Texture induced hardening hides the softening induced by dynamic recrystallization. - Abstract: The present study investigated the influence of the initial orientation on the dynamic recrystallization (DRX) behavior of a Zr-1Sn-0.3Nb alloy. A hot-rolled and annealed Zr sheet was compressed along two directions: along the normal direction so that the grains' -axis was nearly parallel to the loading direction (0° sample) and along the transverse direction so that the grains' -axis was nearly perpendicular to the loading direction (90° sample). The samples were compressed at 700 °C at a strain rate of 1 s{sup −1}. The microstructures at different strains were characterized by the electron backscatter diffraction (EBSD) technique, and conventional dislocation analysis using transmission electron microscope (TEM) was performed. A threshold value of grain orientation spread (GOS) equaled to 5° was used to distinguish the dynamically recrystallized grains from the deformed matrix. The results revealed that the DRX behavior strongly depended on the initial orientation. The Schmid factor analysis and TEM observation confirmed that pyramidal slip operated from the first stage of deformation in the 0° sample but not in the 90° sample. For the 0° sample, in the early and medium stages of deformation, due to the high stored energy caused by the operation of pyramidal slip, DDRX was mainly contributed to the formation of new fine grains. However, in the later stage of deformation, the DRX mechanism changed from DDRX to CDRX. In the 90° sample, although DDRX featured by grain boundary bulging occurred, the main DRX mechanism was CDRX in the whole deformation processing. Moreover, texture induced hardening in the early stage of deformation hides the softening induced by DDRX.

36 MATERIALS SCIENCE↗
DOE OSTI2016

Thermal transport at (001) twist grain boundaries in UO{sub 2}

The thermal conductivity of the nuclear fuels critically affects performance and safety of the nuclear reactor and thus continues to attract interest of engineers and researches. In spite of the large volume of experimental data on the thermal transport properties in UO{sub 2}, new discoveries in recent years include anisotropic thermal conductivity, and unexpectedly large contribution of the optical phonons to thermal transport. On the other hand, advances in computer power allow to simulate directly from atomic level the effect of structural defects such as grain boundaries, dislocations and pores on the thermal conductivity in UO{sub 2}. Unfortunately, such simulations do not provide detailed information about phonon scattering processes, which are important for the complete understanding of the thermal transport and generation of the physics-based thermal transport models in nuclear performance codes. In this work, we apply phonons wave-packet (PWD) molecular dynamics simulation technique in order to elucidate the individual phonons contribution to the thermal transport through the grain boundaries (GB) in UO{sub 2}. In this work we elucidated the effect of the grain boundary atomic structure on the details of the thermal conductance through the interface. Namely, we demonstrated that transmission coefficient as a function of the wave vector is a strong function of the disorder at the interface: for ideally structured GBs it has sharp peaks and pronounced valleys. Such structure disappears upon introduction of the disorder near the interface, and as a result transmission coefficients behave very similarly between GBs of different misorientation, but the same degree of disorder. Kapitza conductance through these GBs is also nearly identical. It is unlikely for experimentally observed GBs to be atomically sharp, and thus Kapitza conductance in polycrystalline UO{sub 2} can be considered misorientation independent with good accuracy, and it does not to be accounted for in physics-based thermal transport model for fuel performance codes. (authors)

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗