Grain shapes are acknowledged to impact nanomaterials' overall properties. Research works on this issue include grain-elongation and grain-strain measurements and their impacts on nanomaterials' mechanical properties. This paper proposes a stochastic model for grain strain undergoing severe plastic deformation. Most models deal with equivalent radii assuming that nanomaterials' grains are spher...

The microstructure development under plastic deformation up to large strains is modelled by means of a four-component reaction kinetics for the densities of mobile and immobile dislocations and disclinations. The resulting system of nonlinear differential equations is able to describe the transition from a dislocation-dominated to a disclination-controlled kinetics running into a (quasi-)statio...

A system of four coupled rate equations for the development of the densities of mobile and redundant dislocations and of mobile and immobile disclinations with time or strain is proposed to describe the microstructure evolution up to large strains. The densities of redundant dislocations and of immobile disclinations are connected to ow stress contributions with the help of Mughrabi's composite...

This paper reports a dramatic increase in the grain boundary strengthening or Hall-Petch coefficient, K, by systematically investigating effect of Al addition on tensile yield strength CoFeN...

The dependency of uniform corrosion of structural steel on the average grain size (D) should be quantified for design purposes. In the present work, a spectrum of grain sizes was obtained by simple heat treatment routes in st37 structural steel. It was revealed that the corrosion current density (icorr) increased by grain refinement, which was related to the increased density of grain boundarie...

We posited that the grain size dependence of tensile necking stress, as determined by Considère criterion for plastic instability, is a more meaningful characteristic Hall–Petch (H–P) effect than yield stress or 0.2% proof stress. An inverse square-root on was derived from dislocation dynamics-based constitutive model. In this model, enters indirectly via evolution density. Model predictions we...

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 reverse Hall-Petch effect — a softening of the metal when the grain size is reduced. The limitations of computer simulations are discussed, with a particular fo...