相关论文: The Hall-Petch effect as a manifestation of the ge…
The Hall-Petch effect has been described for the past sixty years as a dependence of the strength of polycrystalline metals on the inverse square-root of grain size d. The value of the coefficient of the dependence has been the subject of…
Small-scale mechanical behaviour shows significant departures from classical elastic-plastic theory. In a remarkable number of instances, the strength of a material appears to scale as the reciprocal square root of the smallest length…
The statistical-thermodynamic dislocation theory developed in previous papers is used here in an analysis of yielding transitions and grain-size effects in polycrystalline solids. Calculations are based on the 1995 experimental results of…
The relationship between grain size and yield strength of metals follows the Hall-Petch relationship {\sigma} = {\sigma}0 + kd^-0.5; however, the specific physical factors that affect the coefficients {\sigma}0 and k of this relationship…
The role of grain size in determining fracture toughness in metals is incompletely understood with apparently contradictory experimental observations. We study this grain-size dependence computationally by building a model that combines the…
The generalized eguation that describes the yield stress dependence upon the grain size in the wide range of grain sizes has been obtained. There are two critical grain sizes that corresponds to the changes in strengthening mechanism. The…
Incorporating the bond-order-length-strength correlation mechanism [Sun CQ, Prog Solid State Chem 35, 1 -159 (2007)] and Borns criterion for melting [J. Chem. Phys. 7, 591(1939)] into the conventional Hall-Petch relationship has turned out…
We present atomistic simulations for the mechanical response of ultra nanocrystalline diamond, a polycrystalline form of diamond with grain diameters of the order of a few nm. We consider fully three-dimensional model structures, having…
In recent years it has become possible to study the properties of nanocrystalline metals through atomic-scale simulations of systems with realistic grain sizes. A brief overview of the main results is given, such as the observation of a…
The strength of most metals used in daily life scales with either an internal or external length scale. Empirically, this is characterized by power-laws persisting to six orders of magnitude in both strength and length scale. Attempts at…
We study the finite-size scaling behaviour at the critical point, resulting from the addition of a homogeneous size-dependent perturbation, decaying as an inverse power of the system size. The scaling theory is first formulated in a general…
In the framework of the suggested in [arxiv:1803.08247 [cond-mat.mtrl-sci]] statistical theory of the equilibrium flow stress, including yield strength, ${\sigma}_y$, of polycrystalline materials under quasi-static (in case of tensile…
The Hall effect, ever intriguing since its discovery, has spurred the exploration of its phenomena, intensified by advances in topology and novel materials. Differentiating the ordinary Hall effect from extraordinary properties like the…
The theory of the intrinsic Hall effect, both linear and nonlinear, is rooted in a geometry which is defined in the Bloch-vector parameter space; the formal expressions are mostly derived from semiclassical concepts. When disorder and…
We measure magnetic field dependence of the Hall angle in a metallic ferromagnetic nanomagnet with stable local magnetic moments where the adopted mechanisms of Hall effect predict linear plus a constant dependence on the external field…
We show that a two-dimensional spin-orbit-coupled system in the presence of a charge/spin-density wave with a wave-vector perpendicular to an applied electric field supports bulk manifestations of the direct/inverse spin-Hall effect. We…
We demonstrate theoretically how a two-dimensional electron gas can be used to probe local potential profiles using the Hall effect. For small magnetic fields, the Hall resistance is inversely proportional to the average potential profile…
Ultrafine-grained Al alloys produced by high pressure torsion are found to exhibit a very high strength, considerably exceeding the Hall-Petch predictions for the ultrafine grains. The phenomena can be attributed to the unique combination…
In order to make argumentation-based inference contestable, it is crucial to explain what changes can achieve a desired (instead of the contested) inference result. To this end, we introduce strength change explanations for quantitative…
During plastic deformation of granular materials due to loading, the stress-strain and strength characteristics of sand grains are influenced with grain size, their distribution and packing. Also the macroscopic behaviour of granular…