Abstract Plastic yielding of amorphous solids occurs by power-law distributed deformation avalanches whose universality is still debated. Experiments and molecular dynamics simulations are hampered limited statistical samples, although existing stochastic models give precise exponents, they require strong assumptions about fixed directions, at odds with the isotropy materials. Here, we introduce a fully tensorial, mesoscale model for plasticity that links physics plastic to engineering...

Abstract Crystalline defects, such as line-like dislocations, play an important role for the performance and reliability of many metallic devices. Their interaction evolution still poses a multitude open questions to materials science physics. In-situ transmission electron microscopy (TEM) experiments can provide insights into how dislocations behave move. The analysis individual video frames from useful but is limited by capabilities automated identification, digitization, quantitative...

Determining, understanding, and predicting the so-called structure–property relation is an important task in many scientific disciplines, such as chemistry, biology, meteorology, physics, engineering, materials science. Structure refers to spatial distribution of, e.g., substances, material, or matter general, while property a resulting characteristic that usually depends non-trivial way on details of structure. Traditionally, forward simulations models have been used for tasks. Recently,...

Dislocation systems exhibit well-known scaling properties such as the Taylor relationship between flow stress and dislocation density, 'law of similitude' linking to characteristic wavelength patterns. Here, we discuss origin these properties, which can be related generic invariance equations evolution discrete systems, their implications for a wide class models microstructure evolution. We demonstrate that under certain conditions simulations carried out at different stress, density strain...

The spontaneous emergence of heterogeneous dislocation patterns is a conspicuous feature plastic deformation and strain hardening crystalline solids. Despite long-standing efforts in the materials science physics defect communities, there no general consensus regarding physical mechanism which leads to formation patterns. In order establish fundamental mechanism, we formulate an extremely simplified, minimal model investigate based on continuum theory fluxes curved dislocations. We...

Crystal plasticity is governed by the motion of lattice dislocations. Although continuum theories static dislocation assemblies date back to 1950s, line-like character these defects posed serious problems for development a theory which based on averaged dynamics systems. Only recently geometrical problem performing meaningful averages over systems moving, oriented lines has been solved. Such averaging leads definition density tensor second order along with its evolution equation. This can be...

Dislocations -- the carrier of plastic deformation are responsible for a wide range mechanical properties metals or semiconductors. Those line-like objects tend to form complex networks that very difficult characterize link macroscopic on specimen scale. In this work machine learning based approach classification coarse-grained dislocation microstructures in terms different density field variables is used. The performance algorithm combined with domain knowledge from underlying physics helps...

The analysis of microscopy images has always been an important yet time consuming process in materials science. Convolutional Neural Networks (CNNs) have very successfully used for a number tasks, such as image segmentation. However, training CNN requires large amount hand annotated data, which can be problem material science data. We present procedure to generate synthetic data based on ad hoc parametric modelling enhancing generalization trained neural network models. Especially situations...

Metal plasticity is governed by the motion of dislocations, and predicting interactions resulting collective dislocations a major task in understanding modeling plastically deforming materials. This has, despite all efforts advances last few decades, not yet been fully accomplished. The reason for this that discrete models which describe dislocation system with high accuracy are only computationally feasible small systems, strains, strain rates. Classical continuum do suffer from these...

The increasing demand for materials with well-defined microstructure, accompanied by the advancing miniaturization of devices, is reason growing interest in physically motivated, dislocation-based continuum theories plasticity. In recent years, various advanced have been introduced, which are able to described motion straight and curved dislocation lines. focus this paper question how include fundamental properties discrete dislocations during their interaction a dynamics (CDD) theory. our...

In situ straining experiments were performed in a TEM on an equimolar CoCrFeMnNi (Cantor) high entropy alloy at room and cryogenic temperature. Perfect partial dislocation activity recorded both cases. Twinning directly follows the development of shearing that has various origins (perfect splitting, anchoring). It is shown that, although twinning more frequently observed liquid nitrogen temperature, its prevalence depends mainly crystal orientation. As result, perfect plasticity are likely...

High entropy alloys are a class of materials with many significant improvements in terms mechanical properties as compared to "classical" alloys. The corresponding structure-property relations not yet entirely clear, but it is commonly believed that the good performance strongly related dislocation interactions complex energy landscape formed due alloying. Although in-situ Transmission Electron Microscopy (TEM) allows high-resolution studies structure and dynamics moving dislocations makes...

Abstract A macroscopically nominal flat surface is rough at the nanoscale level and consists of nanoasperities. Therefore, frictional properties macroscale-level are determined by mechanical behaviors nanoasperity contact pairs under shear. In this work, we first used molecular dynamics simulations to study non-adhesive shear between single pairs. Subsequently, estimate friction coefficient surfaces, implemented behavior a pair into Greenwood-Williamson-type statistical model. By employing...