相关论文: Vacancies making jerky flow in complex alloys
The behavior of cross-linking polymer solutions as they transition from liquid-like to solid-like material in flow determines success or failure in several applications. Dilute polymer solutions flow easily, while concentrated polymers or…
The present work deals with the microstructure and texture evolutions of a TWIP high entropy alloy at various temperatures. Toward this end, the tensile tests were conducted at temperatures ranging from 298 to 873 K under the strain rate of…
We investigate, via three-dimensional atomistic computer simulations, phase separation in an alloy under external load. A regular two-dimensional array of cylindrical precipitates, forming a mesoscopic precipitate lattice, evolves in the…
The mean-first-passage-times (MFPTs) for a vacancy that diffuses (via one- and six-jump cycles) in a two dimensional ordered binary alloy are evaluated using the properties of random walks on networks. We investigate the effect of…
Understanding the nature and behavior of vacancy-like defects in epitaxial GeSn metastable alloys is crucial to elucidate the structural and optoelectronic properties of these emerging semiconductors. The formation of vacancies and their…
It was experimentally confirmed that if steel cyclic stress reduces to less than tensile yield stress values, i.e. in case of high-cycle fatigue, the mechanism of fracture changes from dislocation to vacancy one. This conclusion was based…
The supersolid state of matter, exhibiting non-dissipative flow in solids, has been elusive for thirty five years. The recent discovery of a non-classical moment of inertia in solid 4He by Kim and Chan provided the first experimental…
Cessation of flow in simple yield stress fluids results in a complex stress relaxation process that depends on the preceding flow conditions and leads to finite residual stresses. To assess the microscopic origin of this phenomenon, we…
Understanding ventilation strategy of a supercavity is important for designing high-speed underwater vehicles wherein an artificial gas pocket is created behind a flow separation device for drag reduction. Our study investigates the effect…
Columnar crystals contain defects in the form of vacancy/interstitial loops or strings of vacancies and interstitials bounded by column ``heads'' and ``tails''. These defect strings are oriented by the columnar lattice and can change size…
Shallow flows are common in natural and human-made environments. Even for simple rectangular shallow reservoirs, recent laboratory experiments show that the developing flow fields are particularly complex, involving large-scale turbulent…
The influence of the surface pre-deformation on jerky flow caused by the Portevin-Le Chatelier (PLC) effect was investigated using flat tensile specimens of an Al-Mg alloy. Although jerky flow represents a macroscopic plastic instability,…
Polymer solutions are often injected in porous media for applications such as oil recovery and groundwater remediation. As the fluid navigates the tortuous pore space, elastic stresses build up, causing the flow to become unstable at…
We present experimental results on the relaxation dynamics of vesicles subjected to a time-dependent elongation flow. We observed and characterized a new instability, which results in the formation of higher order modes of the vesicle shape…
We have used the indium/copper surface alloy to study the dynamics of surface vacancies on the Cu(001) surface. Individual indium atoms that are embedded within the first layer of the crystal, are used as probes to detect the rapid…
Compared to cubic metals, whose primary slip mode includes twelve equivalent systems, the lower crystalline symmetry of hexagonal close-packed metals results in a reduced number of equivalent primary slips and anisotropy in plasticity,…
Creep-fatigue interaction in single-crystal nickel superalloys is difficult to predict because the response depends on the combined effects of loading parameters, hold time, temperature, and the underlying deformation mechanisms. This is…
We present results of kinetic lattice Monte Carlo (KLMC) simulations of substitutional arsenic diffusion in silicon mediated by lattice vacancies. Large systems are considered, with 1000 dopant atoms and long range \textit{ab initio}…
Fatigue simulation requires accurate modeling of unloading and reloading. However, classical ductile damage models treat deformations after complete failure as irrecoverable -- which leads to unphysical behavior during unloading. This…
Glide and climb of quantum dislocations under finite external stress, variation of chemical potential and bias (geometrical slanting) in Peierls potential are studied by Monte Carlo simulations of the effective string model. We treat on…