相关论文: Effects of Applied Load on Formation and Reorienta…
One of the main degradation mechanisms of the zirconium alloys used in nuclear reactors is hydrogen embrittlement and hydride formation. The formation of zirconium hydrides is accompanied by a transformation strain, the effects of which on…
Hydride precipitation in zirconium cladding materials can damage their integrity and durability.Service temperature and material defects have a significant effect on the dynamic growth of hydrides. In this study, we have developed a phase…
Microstructure and crystallography of {\delta} phase hydrides in as-received fine grain and 'blocky' alpha large grain Zircaloy-4 (average grain size ~11 {\mu}m and >200 {\mu}m, respectively) were examined using electron backscatter…
A model for precipitation of the plate-shaped second-phase under applied stress is presented. The precipitates in the matrix-precipitate system are represented by their local volume fraction and an orientation parameter that defines the…
Computational models are used here for simulating diffusion-controlled redistribution of hydrogen that is picked up by zirconium-base nuclear fuel cladding during light water reactor operation. Axial localization of hydrogen, leading to…
The accurate prediction of solid-solid structural phase transitions at finite temperature is a challenging task, since the dynamics is so slow that direct simulations of the phase transitions by first-principles (FP) methods are typically…
We present a kinetic model for solid state phase transformation (alpha<-->beta) of common zirconium alloys used as fuel cladding material in light water reactors. The model computes the relative amounts of beta or alpha phase fraction as a…
In this study, we employ high-energy X-ray characterization to examine the role of relatively large amounts of intragranular lattice misorientation -- present after many thermomechanical processes -- on the micromechanical response of…
High-energy synchrotron x-rays are used to track grain rotations and the micromechanical evolution of a hexagonal Ti-7Al microstructure as it is cyclically loaded below its macroscopic yield stress. The evolution of the grains through 200…
Zirconium alloys are used as nuclear fuel cladding material due to their mechanical and corrosion resistant properties together with their favorable cross-section for neutron scattering. At running conditions, however, there will be an…
The interactions between {\delta}-hydrides and plastic slip in a commercial zirconium alloy, Zircaloy-4, under stress were studied using in situ secondary electron microscope (SEM) micropillar compression tests of single crystal samples and…
The tetragonal to monoclinic phase transformation of zirconia has been the subject of extensive studies over the last 20 years [1-4]. The main features of the transformation have been identified and its martensitic nature is now widely…
Large single crystals of natural zircon were shock-loaded at 13.6 and 51.3 GPa in planar geometry. No structural changes were observed after loading at 13.6 GPa. Loading to 51.3 GPa resulted in zircon transformation to a denser…
Atomistic simulations, based either on an empirical interatomic potential or on ab initio calculations, are used to study the pyramidal glide of a 1/3 <1-210> screw dislocation in hexagonal close-packed zirconium. Generalized stacking fault…
Strain engineering enables precise, energy-efficient control of nanoscale magnetism. However, unlike well-studied strain-dislocation interactions in mechanical deformation, the spatial evolution of strain-induced spin rearrangement remains…
A phase field model is presented to investigate dislocation formation (coherency loss) and workhardening in two-phase binary alloys. In our model the elastic energy density is a periodic function of the shear and tetragonal strains, which…
We show that simple 2 and 3-layer flux-transport dynamos, when forced at the top by a poloidal source term, can produce a widely varying amplitude of toroidal field at the bottom, depending on how close the meridional flow speed of the…
The influence of alternating shear orientation and strain amplitude of cyclic loading on yielding in amorphous solids is investigated using molecular dynamics simulations. The model glass is represented via a binary mixture that was rapidly…
We use powder x-ray diffraction to study the effect of pressure on the crystal structure of the honeycomb rhodate Li$_2$RhO$_3$. We observe low-pressure ($P$$<$$P_{c1}$ = 6.5 GPa) and high-pressure ($P$$>$$P_{c2}$ = 14 GPa) regions…
A multiscale approach based on the phase-field model is developed to simulate homogeneous and heterogeneous formation of {\theta}' precipitates during high temperature ageing in Al-Cu alloys. The model parameters that determine the…