A5012315225- Microstructure and mechanical properties
- Intermetallics and Advanced Alloy Properties
- Metal and Thin Film Mechanics
- High Temperature Alloys and Creep
- Nuclear Materials and Properties
- Fusion materials and technologies
- Advanced Materials Characterization Techniques
- Aluminum Alloys Composites Properties
- nanoparticles nucleation surface interactions
- Ion-surface interactions and analysis
- Hydrogen embrittlement and corrosion behaviors in metals
- Microstructure and Mechanical Properties of Steels
- Nanoporous metals and alloys
- High-Temperature Coating Behaviors
- High-Velocity Impact and Material Behavior
- High Entropy Alloys Studies
- Anodic Oxide Films and Nanostructures
- Rare-earth and actinide compounds
- Semiconductor materials and interfaces
- MXene and MAX Phase Materials
- Advanced materials and composites
- Boron and Carbon Nanomaterials Research
- Electrocatalysts for Energy Conversion
- Quasicrystal Structures and Properties
- Diamond and Carbon-based Materials Research
Virginia Tech
2015-2024
Pennsylvania State University
2018
Washington State University
2018
Montanuniversität Leoben
2018
Rensselaer Polytechnic Institute
2018
New York University Press
2018
MicroVision (United States)
2018
Virginia College
2010
Imperial College London
2004
Los Alamos National Laboratory
2004
We demonstrate an approach to the development of many-body interatomic potentials for monoatomic metals with improved accuracy and reliability. The functional form is that embedded-atom method, but interesting features are as follows: (1) database used a potential includes both experimental data large set energies different alternative crystalline structures material generated by ab initio calculations. introduce rescaling distances in attempt improve compatibility between data. (2) optimum...
We present a detailed analysis of grain-boundary structures in computer-generated Cu and Ni three-dimensional nanocrystalline samples. The study includes both totally random textured microstructures with grain sizes the range 5--12 nm. A direct visualization technique is used at atomic scale for studying structural features. focuses on determining presence regions boundary exhibiting order units normally expected high-angle boundaries. For low-angle boundaries we investigate dislocation...
The mechanisms of plastic deformation in nanocrystalline Ni are studied using three-dimensional molecular-dynamics computer simulations for samples with mean grain sizes ranging from 3 to 12 nm under uniaxial load at finite temperatures. At the lower limit this size range, we observe a regime controlled by intergrain sliding; upper limit, however, two competing mechanisms: sliding and dislocation emission boundaries (GB's). latter mechanism constitutes transition behavior, precursor...
The key to perfect radiation endurance is recovery. Since surfaces are sinks for defects, a porous material with high surface volume ratio has the potential be extremely tolerant, provided it morphologically stable in environment. Experiments and computer simulations on nanoscale gold foams reported here show existence of window parameter space where tolerant. We analyze these results terms model irradiation response that quantitatively locates such appears consequence combined effect two...
The strengthening effect of twins in nanocrystalline metals has been reported both experiment and simulation. While are mostly considered as effective barriers to dislocation slip transfer, they can also provide nucleation sites for dislocations or migrate during the deformation process, thereby contributing plasticity. By comparing twinned nontwinned samples, we study on behavior Cu Pd using atomistic simulations. shows hardening due presence twins, opposite effect. A quantitative analysis...
Irradiation assisted stress-corrosion cracking (IASCC) is a form of intergranular stress corrosion that occurs in irradiated austenitic alloys. It requires an microstructure along with high temperature water and stress. The process ubiquitous it wide range alloys chemistries, but only when the alloy irradiated. Despite evidence this degradation mode dates back to 1960s, mechanism by which has remained elusive. Here, using resolution electron backscattering detection analyze local...
Abstract Tailored control of the pattern forming instability that is initiated through selective dissolution in metal alloys has enabled production high-performing nanoporous metals. Nanoporous metals are “forged fire,” evolving from exposure to harsh environments. This makes them uniquely adapted extreme conditions with potential for service applications require tolerance corrosive environments, high-rate mechanical loading, and high-energy irradiation. metastable structures successful...
Crack propagation studies in nanocrystalline Ni samples with mean grain sizes ranging from 5 to 12 nm are reported using atomistic simulations. For all pure intergranular fracture is observed. Intergranular shown proceed by the coalescence of microvoids formed at boundaries ahead crack. The energy released during higher than Griffith value, indicating an additional grain-boundary accommodation mechanism.
A simple many-body interatomic potential is proposed. This an empirical extension of the embedded-atom method (EAM). The EAM models lattice energy and elastic compressibility using a pair interaction plus term. It does not include any contribution terms to crystal shear. included in model developed here. implies simplified treatment angularity inherent covalent bonding transition metals. set potentials deduced for bcc Nb, Fe, Cr. While previous works literature has already been successfully...
We carried out classical atomistic studies of crack propagation in fully three-dimensional nanocrystalline $\ensuremath{\alpha}$-Fe (body-centered cubic structure) to examine the influence temperature and average grain size on fracture mechanisms properties. Digital samples with sizes ranging from 6 12 nm are reported at temperatures 100 K 600 using simulations. For all sizes, a combination intragranular intergranular is observed. Mechanisms such as boundary accommodation, triple junction...