相关论文: Temperature-activated dislocation avalanches signa…
The thermally activated motion of dislocations across fields of obstacles distributed at random and in a correlated manner, in separate models, is studied by means of computer simulations. The strain rate sensitivity and strength are…
The crystallographic and magnetic properties of the cleavable 4d3 transition metal compound a-MoCl3 are reported, with a focus on the behavior above room temperature. Crystals were grown by chemical vapor transport and characterized using…
Numerical simulation of the dislocation motion in 2D Frenkel - Kontorova (FK) model in the thermostat shows an unusual dynamical behavior. It appears that ''kink'' regime of dislocation gliding takes place in a certain region of parameters…
This work presents an open source, dislocation density based crystal plasticity modeling framework, $\rho$-CP. A Kocks-type thermally activated flow is used for accounting for the temperature and strain rate effects on the crystallographic…
The present paper is concerned with the development of a micromechanical model of the hardening, rate-sensitivity and thermal softening of bcc crystals. In formulating the model we specifically consider the following unit processes:…
Large-scale atomistic calculations, using empirical potentials for modeling semiconductors, have been performed on a stressed system with linear surface defects like steps. Although the elastic limits of systems with surface defects remain…
Radiation creep and swelling are irreversible deformation phenomena occurring in materials irradiated even at low temperatures. On the microscopic scale, energetic particles initiate collision cascades, generating and eliminating defects…
Measurements of conductance $G$ on short, wide, high-mobility Si-MOSFETs reveal both a two-dimensional metal-insulator transition (MIT) at moderate temperatures (1 $<~ T <$ 4~K) and mesoscopic fluctuations of the conductance at low…
Pinning interaction between a screw dislocation and a void in fcc copper is investigated by means of molecular dynamics simulation. A screw dislocation bows out to undergo depinning on the original glide plane at low temperatures, where the…
Large scale numerical simulations are used to study the elastic dynamics of two-dimensional vortex lattices driven on a disordered medium in the case of weak disorder. We investigate the so-called elastic depinning transition by decreasing…
The deformation behavior of single crystal and nanocrystalline nickel were studied using in situ micropillar compression experiments from quasi-static to high strain rates up to 10^3 s-1. Deformation occurred by dislocation slip activity in…
The viscoplastic behavior of polycrystalline Mg$_2$SiO$_4$ wadsleyite aggregates, a major high pressure phase of the mantle transition zone of the Earth (depth range: 410 -- 520 km), is obtained by properly bridging several scale transition…
A mesoscale study of a single crystal nickel-base superalloy subjected to an industrially relevant process simulation has revealed the complex interplay between microstructural development and the micromechanical behaviour. As sample gauge…
We investigate the strain-rate-dependent mechanical behavior and deformation mechanisms of a refractory high entropy alloy, Ti29Zr24Nb23Hf24 (at.%), with a single-phase body-centered cubic (BCC) structure. High-temperature compression tests…
The process of fracture in ductile metals involves the nucleation, growth, and linking of voids. This process takes place both at the low rates involved in typical engineering applications and at the high rates associated with dynamic…
The remarkable finding of this work is the linear correlation between the critical temperature of superconducting (SC) transition, Tc, and the room-temperature half-width of angular correlation of positron annihila- tion phonons (ACPAP),…
Two recent electronic transport experiments from Columbia University and Harvard University have reported record high mobility and low channel densities in transition metal dichalcogenide (TMD) WSe$_2$ monolayers [J. Pack, et al.,…
In situ straining experiments were performed in a TEM on an equimolar CoCrFeMnNi (Cantor) high entropy alloy at room and cryogenic temperature. Perfect and partial dislocation activity were recorded in both cases. Twinning directly follows…
Jogs, atomic-scale steps on dislocations, play an important role in crystal plasticity, yet they are often ignored in discrete dislocation dynamics (DDD) simulations due to their small sizes. While jogs on screw dislocations are known to…
We demonstrate, through 3-dimensional discrete dislocation dynamics simulations, that the com- plex dynamical response of nano and micro crystals to external constraints can be tuned. Under load rate control, strain bursts are shown to…