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Related papers: Scale-bridging dislocation plasticity in MgO at ro…

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Dislocation patterning and self-organization during plastic deformation are associated with work hardening, but the exact mechanisms remain elusive. This is partly because studies of the structure and local strain during the initial stages…

Plasticity in zirconium alloys is mainly controlled by the interaction of 1/3 1210 screw dislocations with oxygen atoms in interstitial octahedral sites of the hexagonal close-packed lattice. This process is studied here using ab initio…

Materials Science · Physics 2017-05-12 Nermine Chaari , David Rodney , Emmanuel Clouet

Dimension reduction procedure is the recipe to represent defects in two dimensional dislocation dynamics according to the changes in the geometrical properties of the defects triggered by different conditions such as radiation, high…

Materials Science · Physics 2015-01-30 Ahmet Ilker Topuz

The kinetics of dislocations is studied with computer simulation at loadings of different intensity. It is established that the dislocations have a few different structural states. The dislocations "with the micropore" play important role…

Materials Science · Physics 2007-05-23 L. S. Metlov

Although titanium nitride (TiN) is among the most extensively studied and thoroughly characterized thin-film ceramic materials, detailed knowledge of relevant dislocation core structures is lacking. By high-resolution scanning transmission…

Dynamic shear banding under adiabatic conditions in a mesoscale polycrystalline aggregate is studied using a model of mesoscale dislocation mechanics and experiments. The model involves a length scale related to hardening induced by…

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…

Geophysics · Physics 2020-12-03 O. Castelnau , K. Derrien , S Ritterbex , P. Carrez , P. Cordier , H. Moulinec

Precipitation strengthening is one of the most effective methods to design alloys with the desired combination of strength and ductility. The main mechanism of strengthening is generally known to be the interaction between dislocations and…

Materials Science · Physics 2018-09-05 Amirreza Keyhani

Defects are inevitable during the manufacturing processes of materials. Presence of these defects and their dynamics significantly influence the responses of materials. A thorough understanding of dislocation dynamics of different types of…

Materials Science · Physics 2024-08-28 Santosh Chhetri , Maryam Naghibolhosseini , Mohsen Zayernouri

We develop a strain gradient plasticity formulation for composite materials with spatially varying volume fractions to characterize size effects in functionally graded materials (FGMs). The model is grounded on the mechanism-based strain…

Materials Science · Physics 2018-07-27 Tittu V. Mathew , Sundararajan Natarajan , Emilio Martínez-Pañeda

Dislocation engineering has the potential to open new avenues toward the exploration and modification of the properties of quantum materials. Strontium titanate (SrTiO3, STO) and potassium tantalate (KTaO3, KTO) are incipient ferroelectrics…

We report the first ab initio density-functional study of <111> screw dislocations cores in the bcc transition metals Mo and Ta. Our results suggest a new picture of bcc plasticity with symmetric and compact dislocation cores, contrary to…

Materials Science · Physics 2009-10-31 Sohrab Ismail-Beigi , T. A. Arias

During plastic deformation of metals and alloys, dislocations self-organise in cells, which subsequently continuously decrease in size. How and when these processes take place has remained elusive, because observations of the structural…

The present paper studies non-uniform plastic deformations of crystals undergoing anti-plane constrained shear. The asymptotically exact energy density of crystals containing a moderately large density of excess dislocations is found by the…

Materials Science · Physics 2018-01-17 Khanh Chau Le , Yinguang Piao

Viscoplastic flow of polycrystalline metallic materials is the result of motion and interaction of dislocations, line defects of the crystalline structure. In the microstructural (physics-based) constitutive model presented in this paper,…

Materials Science · Physics 2018-09-11 S. Amir H. Motaman , Ulrich Prahl

The gradient crystal plasticity framework of Wulfinghoff et al. [53] incorporating an equivalent plastic strain and grain boundary yielding, is extended with additional grain boundary hardening. By comparison to averaged results from many…

Computational Physics · Physics 2015-12-18 E. Bayerschen , M. Stricker , S. Wulfinghoff , D. Weygand , T. Böhlke

Conventional discrete-to-continuum approaches have seen their limitation in describing the collective behaviour of the multi-polar configurations of dislocations, which are widely observed in crystalline materials. The reason is that…

Materials Science · Physics 2016-04-12 Stephen Jonathan Chapman , Yang Xiang , Yichao Zhu

Over the past decades, discrete dislocation dynamics simulations have been shown to reliably predict the evolution of dislocation microstructures for micrometer-sized metallic samples. Such simulations provide insight into the governing…

Strain hardening is a key feature observed in many rocks deformed in the so-called ``semi-brittle'' regime, where both crystal plastic and brittle deformation mechanisms operate. Dislocation storage has long been recognised as a major…

Geophysics · Physics 2025-02-14 Nicolas Brantut

An equimolar NiCoFeCrGa high entropy alloy having dual-phase homogeneous components was studied, where the constituent phases exhibit distinct mechanical properties. Micropillars with various diameters were created from two differently heat…

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