Features of the behavior of symmetrical tilt grain boundaries in BCC and FCC metals under shear loading. Molecular dynamics study

2014 ◽  
Author(s):  
Andrey I. Dmitriev ◽  
Anton Yu. Nikonov
Keyword(s):  
Molecular Dynamics ◽  
Grain Boundaries ◽  
Shear Loading ◽  
Fcc Metals ◽  
Symmetrical Tilt

scholarly journals FEATURES OF THE Σ5 AND Σ9 GRAIN BOUNDARIES MIGRATION IN BCC AND FCC METALS UNDER SHEAR LOADING – A MOLECULAR DYNAMICS STUDY

2017 ◽  
Vol 15 (2) ◽  
pp. 285
Author(s):  
Andrey I. Dmitriev ◽  
Anton Yu. Nikonov
Keyword(s):  
Molecular Dynamics ◽  
Plastic Deformation ◽  
Molecular Dynamics Simulation ◽  
Grain Boundaries ◽  
Shear Loading ◽  
External Stress ◽  
Dynamics Simulation ◽  
Fcc Metals ◽  
Symmetrical Tilt ◽  
Fcc Metal

Molecular dynamics simulation of metallic bicrystals has been carried out to investigate the behavior of the symmetrical tilt grain boundaries under shear loading. Σ5 and Σ9 grain boundaries in Ni and α-Fe were analyzed. It is found that behavior of the defect depends not only on the structure of boundaries but also on the type of crystal lattice. In particular it is shown that under external stress the grain boundary (GB) behaves differently in the BCC and FCC metal. A comparison of the values of displacement of various types of GB due to their migration caused by shear deformation is carried out. The results can help us to understand the features of the plastic deformation development in nanoscale polycrystals under shear loading.

Features of Contact Interaction of BCC and FCC Metals

2015 ◽  
Vol 1098 ◽  
pp. 110-114
Author(s):  
Anton Yu. Nikonov ◽  
Andrey I. Dmitriev ◽  
Igor A. Abrikosov
Keyword(s):  
Molecular Dynamics ◽  
Thin Layer ◽  
Contact Interaction ◽  
Shear Loading ◽  
Surface Layers ◽  
Atomic Lattice ◽  
Interfacial Layers ◽  
Fcc Metals ◽  
Coated Materials ◽  
Bcc Iron

We carried out simulations of contact interaction between BCC iron crystallite and various pure FCC metals under shear loading by means of molecular dynamics. It was shown that the result of this interaction is the transformation of FCC atomic lattice of contacted material into BCC one within a thin layer in the contact zone. The results of simulations can be used to control strength of the interfacial layers of coated materials, as well as to understand the processes which are taking place in surface layers of materials under the contact.

Molecular Dynamics Simulations of Nanocrystalline Nickel and Copper Revealing Different Failure Model of FCC Metals

2009 ◽  
Vol 633-634 ◽  
pp. 31-38
Author(s):  
Ajing Cao
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulations ◽  
Grain Boundaries ◽  
Large Scale ◽  
Uniaxial Tensile ◽  
Face Centered Cubic ◽  
Triple Junctions ◽  
Fcc Metals ◽  
Face Centered ◽  
Dynamics Simulations

We have previously reported that the fracture behavior of nanocrystalline (NC) Ni is via the nucleation and coalescence of nano-voids at grain boundaries and triple junctions, resulting in intergranular failure mode. Here we show in large-scale molecular dynamics simulations that partial-dislocation-mediated plasticity is dominant in NC Cu with grain size as small as ~ 10 nanometers. The simulated results show that NC Cu can accommodate large plastic strains without cracking or creating damage in the grain interior or grain boundaries, revealing their intrinsic ductile properties compared with NC Ni. These results point out different failure mechanisms of the two face-centered-cubic (FCC) metals subject to uniaxial tensile loading. The insight gained in the computational experiments could explain the good plasticity found in NC Cu not seen in Ni so far.

The Causes of Formation of the Triple Junctions of Grain Boundaries Containing Excess Free Volume in fcc Metals at Crystallization

2016 ◽  
Vol 247 ◽  
pp. 3-8 ◽  
Author(s):  
Gennady M. Poletaev ◽  
Darya V. Novoselova ◽  
Valentina M. Kaygorodova
Keyword(s):  
Molecular Dynamics ◽  
Grain Boundaries ◽  
Free Volume ◽  
Crystallization Process ◽  
Triple Junctions ◽  
Phase Density ◽  
Fcc Metals ◽  
Excess Free Volume ◽  
Method Of Molecular Dynamics ◽  
Formation Conditions

The formation conditions of strained (non-equilibrium) triple junctions of grain boundaries were studied by the method of molecular dynamics. It is shown that strained triple junctions, containing excess free volume, mainly forms during crystallization process in the result of "locking" of the liquid phase density at a meeting of the three crystallization fronts and, as a consequence, of the concentration of excess free volume in the triple junction after solidification.

INTERACTION BETWEEN LATTICE DISLOCATIONS AND GRAIN BOUNDARIES IN FCC METALS AND ORDERED COMPOUNDS

1990 ◽  
Vol 51 (C1) ◽  
pp. C1-311-C1-316 ◽  
Author(s):  
B. J. PESTMAN ◽  
J. Th. M. DE HOSSON ◽  
V. VITEK ◽  
F. W. SCHAPINK
Keyword(s):  
Grain Boundaries ◽  
Fcc Metals

A Study on the Uniaxial Tension of FCC Metals at Nano Level Using MD

2008 ◽  
Vol 32 ◽  
pp. 255-258
Author(s):  
Bohayra Mortazavi ◽  
Akbar Afaghi Khatibi
Keyword(s):  
Molecular Dynamics ◽  
Uniaxial Tension ◽  
Md Simulations ◽  
Dynamics Simulation ◽  
Face Centered Cubic ◽  
Engineering Strain ◽  
Fcc Metals ◽  
Engineering Stress ◽  
Nano Science ◽  
Face Centered

Molecular Dynamics (MD) are now having orthodox means for simulation of matter in nano-scale. It can be regarded as an accurate alternative for experimental work in nano-science. In this paper, Molecular Dynamics simulation of uniaxial tension of some face centered cubic (FCC) metals (namely Au, Ag, Cu and Ni) at nano-level have been carried out. Sutton-Chen potential functions and velocity Verlet formulation of Noise-Hoover dynamic as well as periodic boundary conditions were applied. MD simulations at different loading rates and temperatures were conducted, and it was concluded that by increasing the temperature, maximum engineering stress decreases while engineering strain at failure is increasing. On the other hand, by increasing the loading rate both maximum engineering stress and strain at failure are increasing.

Molecular dynamics study on the diffusion behavior of Li in the grain boundaries of α-Fe

2016 ◽  
Vol 109-111 ◽  
pp. 678-683 ◽  
Author(s):  
Xingang Yu ◽  
Chengrui Liu ◽  
Tiansi Han ◽  
Xianglai Gan
Keyword(s):  
Molecular Dynamics ◽  
Grain Boundaries ◽  
Diffusion Behavior

Atomic Mechanisms of Grain Boundary Motion

2005 ◽  
Vol 502 ◽  
pp. 157-162 ◽  
Author(s):  
A. Suzuki ◽  
Yuri M. Mishin
Keyword(s):  
Molecular Dynamics ◽  
Grain Boundary ◽  
Geometric Model ◽  
Lattice Rotation ◽  
Shear Stresses ◽  
Translation Rate ◽  
Embedded Atom ◽  
Local Lattice ◽  
Symmetrical Tilt ◽  
Grain Boundary Motion

We present results of atomistic computer simulations of spontaneous and stress-induced grain boundary (GB) migration in copper. Several symmetrical tilt GBs have been studied using the embedded-atom method and molecular dynamics. The GBs are observed to spontaneously migrate in a random manner. This spontaneous GB motion is always accompanied by relative translations of the grains parallel to the GB plane. Furthermore, external shear stresses applied parallel to the GB and normal to the tilt axis induce GB migration. Strong coupling is observed between the normal GB velocity vn and the grain translation rate v||. The mechanism of GB motion is established to be local lattice rotation within the GB core that does not involve any GB diffusion or sliding. The coupling constant between vn and v|| predicted within a simple geometric model accurately matches the molecular dynamics observations.

Sign in / Sign up

Export Citation Format

Share Document