A hierarchical dislocation-grain boundary interaction model based on 3D discrete dislocation dynamics and molecular dynamics

Gao, Yuan; Zhuang, Zhuo; You, Xiaoqing

doi:10.1007/s11433-011-4298-9

Cited by 14 publications

(3 citation statements)

References 32 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…[28] The probability for dislocation-dislocation interaction is higher in FG microstructure compared to that in UFG microstructure as dislocation-GB interaction comes into play. [29][30][31] With ECAP KD having both FG and UFG microstructures, it is possible that the extent of loss of dislocation strengthening is higher in the regions consisting of fine grains in comparison to that in the regions comprising UFGs. Thus, when measuring the bulk hardness of ECAP KD post static recovery (after annealing at 550 °C for 48 h), it is expected that the range of hardness measured is wider.…”

Section: Thermal Stability Of Ecap Kdmentioning

confidence: 99%

Comparison of the Thermal Stability in Equal‐Channel‐Angular‐Pressed and High‐Pressure‐Torsion‐Processed Fe–21Cr–5Al Alloy

Arivu,

Hoffman,

Duan

et al. 2023

Adv Eng Mater

View full text Add to dashboard Cite

Nanostructured steels are expected to have enhanced irradiation tolerance and improved strength. However, they suffer from poor microstructural stability at elevated temperatures. In this study, Fe‐21Cr‐5Al‐0.026C (wt.%) Kanthal D (KD) alloy belonging to a class of (FeCrAl) alloys that are considered for accident tolerant fuel cladding in light water reactors was nanostructured using two severe plastic deformation techniques of equal‐channel angular pressing (ECAP) and high‐pressure torsion (HPT), and their thermal stability at temperatures from 500 oC to 700 oC was studied and compared. ECAP KD was found to be thermally stable up to 500 oC, whereas HPT KD started to lose its stability at 500 oC. Microstructural characterization revealed that ECAP KD underwent recovery at 550 oC and recrystallization above 600 oC, while HPT KD showed continuous grain growth after annealing above 500 oC. Enhanced thermal stability of ECAP KD is attributed to the significant fraction (> 50%) of low‐angle GBs (misorientation angle 2o – 15o) stabilizing the microstructure as a result of their low mobility. Small grain sizes, a high fraction (> 80%) of high‐angle GBs (misorientation angle > 15o) and accordingly a large amount of stored GB energy, serve as the driving force for HPT KD to undergo grain growth as opposed to recrystallization, which is driven by excess stored strain energy.This article is protected by copyright. All rights reserved.

show abstract

Section: Thermal Stability Of Ecap Kdmentioning

confidence: 99%

Comparison of the Thermal Stability in Equal‐Channel‐Angular‐Pressed and High‐Pressure‐Torsion‐Processed Fe–21Cr–5Al Alloy

Arivu,

Hoffman,

Duan

et al. 2023

Adv Eng Mater

View full text Add to dashboard Cite

show abstract

“…In the investigation of discrete dislocation plasticity, a unified computational model for discrete dislocation plasticity was developed by directly combining 3D discrete dislocation dynamics (DDD) and finite element method (FEM) [8]. In this methodology, the discrete dislocation plasticity in a finite crystal was solved under a completed continuum mechanics framework.…”

Section: Dislocation Dynamic Simulation At Sub-micron Scalementioning

confidence: 99%

Recent research progress in computational solid mechanics

Zhuang

Maitireyimu

2012

Chin. Sci. Bull.

Self Cite

View full text Add to dashboard Cite

Computational mechanics has had a profound impact on science and technology over the past five decades. It has numerically transformed much of the classical theory models into practical tools for predicting and understanding the complex engineering and science system. A short review is given in this paper on some recent progress in computational solid mechanics at multi-scales.computational solid mechanics, extended finite element method, molecule dynamic, multi-scales Citation:Zhuang Z, Maitireyium M. Recent research progress in computational solid mechanics. Chin Sci Bull, 2012Bull, , 57: 46834688, doi: 10.1007 Computational mechanics has had a profound impact on science and technology over the past five decades. It has numerically transformed much of the classical Newtonian theory into practical tools for predicting and understanding the complex engineering and science system, which have some limitations using the classic analytical solutions. Finite element methodology (FEM), which is one of the most powerful computation tools, has been widely used in the simulation-based engineering and science. There are a number of methods based on FEM dealing with the problem of material behaviors and structural mechanics, for example, damage and fracture. Since the limitation of FEM is in the continuum problem ranging from micro-meter to macro scales, the molecule dynamic (MD) computation is used at nano-scale research. A short review is given in this paper on the recent progress in computational solid mechanics related to length scales. MD simulation at nano-scaleThe carbon nano-tube (CNT) as a representative nano-scale material was invented twenty years ago. Its material behavior and mechanics has been interested by many researchers and engineers. The investigations were carried out from the aspects of theory, experiment and simulation. Since it is discrete at atomic length, the MD method is the best tool in the numerical analysis. Another purpose using MD simulation is to provide the failure criterion for dislocation initiation in the crystals, which can link the scales from nano-meter to micron. The minimum energy principle for the dislocation nucleation or initiation was predicted for inhomogeneous atomic system [1]. The simulation results illustrated that the thin film is easily nucleated on the surface because the atomic bonds lose. Based on MD simulation at nano-size and theoretical analysis, an investigation of the combined size and rate effects on the mechanical responses of faced cubic crystal (FCC) metals has been made to develop a hyper-surface (Figure 1) crossing the length scales [2]. The high strength and hard toughness properties of crystalline solid were intensively investigated at sub-micron and nanoscales. In these scales, the forms of defects in a crystal material are dislocation and grain boundary. A majority of research papers were focused on the dislocation nucleation and the interactions between dislocation and grain boundary [3]. The yield strength of perfect crystal depends on dislocation nu...

show abstract

“…In this case, the only consideration was the point at which the local stress exceeded the threshold required to overcome the line energy of the geometricallynecessary residual Burgers vector and to overcome the interfacial misfit energy, proportional to the GB free energy [Fan et al, 2012]. More recently, terms have also been added to compensate for the stacking fault energy and provide a more physics-based model for the GB energy term [Gao et al, 2011]. In these models, the GB interfacial structure (comprised of a dislocation array) was not considered.…”

Section: Introductionmentioning

confidence: 99%

Dislocation dynamics in polycrystals with atomistic-informed mechanisms of dislocation - grain boundary interactions

Burbery

Das

et al. 2017

J. Micromech. Mol. Phys.

View full text Add to dashboard Cite

In polycrystalline materials, dislocations can interact with grain boundaries (GBS) through a number of mechanisms including dislocation absorption, pile-up formation, dissociation reactions within the GB plane and (possibly) dislocation nucleation from the interface itself. The effects of dislocation pile-ups contribute significantly to the mechanical behavior of polycrystalline materials by creating back-stresses that inactivate the primary slip systems in the vicinity of the interface, corresponding with the celebrated Hall-Petch relationship between size and strength. However, dislocation pile-ups cannot be contained within the small grain sizes that can be accommodated by molecular dynamics simulations, which to-date remain the primary computational method used to study the discrete structure of GBs.Dislocation dynamics (DD) simulations are a promising framework for computational modeling that are used to provide insights about phenomena that can only be explained from the intermediate scale between atomistic and macro scales. However, a robust framework for modeling dislocation interactions with internal microstructure such as grain boundaries (GBs) has yet to be achieved for 3D models of DD. Furthermore, this is the first implementation which explicitly includes the dislocation content of the interface. The framework described in this paper is effective for studying GBdislocation interactions (including inter-granular effects) and the approach for partitioning the DD simulation domain. To achieve a robust method to differentiate between crystal regions, the present framework utilizes a mesh-based partitioning system. Within each grain, slip systems are determined by the grain orientation. The versatile construction described, allows modeling of an arbitrary crystallography, size and grain geometry. Extrinsic dislocations that intersect the interface are constrained to glide on the line of intersection between the glide plane and GB plane. Atomistically informed criteria for § Corresponding author. N. B. Burbery et al.slip transmission are implemented, based on the geometrically optimal outgoing glide plane which shares a common line of intersection on the GB plane. Slip transmission is only initiated when the resolved shear stress in one of the compatible outgoing slip directions exceeds an approximate threshold resolved shear stress, which is based on observations made with molecular dynamics studies. The primary aim of the present study was to establish a sufficiently 'generic' framework to enable the modelling of various GB structures, polycrystal geometries and crystallographic orientations. The framework described in the present work provides a means to study multi-grain deformation processes governed by dislocations pile-ups at GBs, in detail beyond feasible limits of experiments or atomistic simulation approaches.

show abstract

A hierarchical dislocation-grain boundary interaction model based on 3D discrete dislocation dynamics and molecular dynamics

Cited by 14 publications

References 32 publications

Comparison of the Thermal Stability in Equal‐Channel‐Angular‐Pressed and High‐Pressure‐Torsion‐Processed Fe–21Cr–5Al Alloy

Comparison of the Thermal Stability in Equal‐Channel‐Angular‐Pressed and High‐Pressure‐Torsion‐Processed Fe–21Cr–5Al Alloy

Recent research progress in computational solid mechanics

Dislocation dynamics in polycrystals with atomistic-informed mechanisms of dislocation - grain boundary interactions

Contact Info

Product

Resources

About