A Unified Theory of Grain Boundaries I. Symmetric Tilt Boundaries

1973 ◽  
pp. 423-435
Author(s):  
M. J. Marcinkowski ◽  
K. Sadananda ◽  
Wen Feng Tseng
Keyword(s):  
Grain Boundaries ◽  
Unified Theory ◽  
Symmetric Tilt ◽  
Tilt Boundaries

Atomistic Simulations of [001] Symmetric Tilt Boundaries in Ni3Al

1986 ◽  
Vol 81 ◽  
Author(s):  
S. P. Chen ◽  
A. F. Voter ◽  
D. J. Srolovitz
Keyword(s):  
Grain Boundary ◽  
Grain Boundaries ◽  
Simulation Study ◽  
Atomistic Simulation ◽  
Atomistic Simulations ◽  
Boundary Composition ◽  
Symmetric Tilt ◽  
Tilt Boundaries ◽  
Cohesive Energies

AbstractWe report a systematic atomistic simulation study of [001] symmetric tilt grain boundaries (GB) in Ni3Al, Ni, and Al. We found that the grain boundary energies and cohesive energies of Ni3Al and pure fcc Ni are approximately thesame. Grain boundary energies aid cohesive energies in Ni3Al depends stronglyon the grain boundary composition. The Al-rich boundaries have highest grain boundary energies and lowest cohesive energies. This offers an explanation for the stoichiometric effect on the boron ductilization

scholarly journals MODELING GRAIN BOUNDARIES IN SOLIDS USING A COMBINED NONLINEAR AND GEOMETRICAL METHOD

2005 ◽  
Vol 19 (27) ◽  
pp. 4047-4056 ◽  
Author(s):  
DENIS BOYER ◽  
DAVID ROMEU
Keyword(s):  
Grain Boundaries ◽  
Quantitative Agreement ◽  
Periodic Patterns ◽  
Field Methods ◽  
Ginzburg Landau ◽  
Physical Context ◽  
Symmetric Tilt ◽  
Tilt Boundaries ◽  
Model Equations ◽  
Rayleigh Benard

The complex arrangements of atoms near grain boundaries are difficult to understand theoretically. We propose a phenomenological (Ginzburg–Landau-like) description of crystalline phases based on symmetries and some fairly general stability arguments. This method allows a very detailed description of defects at the lattice scale with virtually no tunning parameters, unlike the usual phase-field methods. The model equations are directly inspired from those used in a very different physical context, namely, the formation of periodic patterns in systems out-of-equilibrium (e.g. Rayleigh–Bénard convection, Turing patterns). We apply the formalism to the study of symmetric tilt boundaries. Our results are in quantitative agreement with those predicted by a recent crystallographic theory of grain boundaries based on a geometrical quasicrystal-like construction. These results suggest that frustration and competition effects near a defect in crystalline arrangements have some universal features, of interest in solids or other periodic phases.

A unified theory of grain boundaries. I. Symmetrie tilt boundaries

1973 ◽  
Vol 17 (2) ◽  
pp. 423-433 ◽  
Author(s):  
M. J. Marcinkowski ◽  
K. Sadananda ◽  
Wen Feng Tseng
Keyword(s):  
Grain Boundaries ◽  
Unified Theory ◽  
Tilt Boundaries

A unified theory of grain boundaries. II. Asymmetric tilt boundaries

1973 ◽  
Vol 18 (1) ◽  
pp. 361-375 ◽  
Author(s):  
M. J. Marcinkowski ◽  
K. Sadananda
Keyword(s):  
Grain Boundaries ◽  
Unified Theory ◽  
Tilt Boundaries

Atomic Structure Calculations of the Interaction between Lattice Dislocations and Grain Boundaries

1990 ◽  
Vol 193 ◽  
Author(s):  
B. J. Pestman ◽  
J. Th. M. De Hosson ◽  
V. Vitek ◽  
F. W. Schapink
Keyword(s):  
Grain Boundaries ◽  
Atomic Structure ◽  
Many Body ◽  
Screw Dislocations ◽  
Symmetric Tilt ◽  
Ordered Alloys ◽  
Atomistic Calculations ◽  
Tilt Boundaries ◽  
Atomic Structure Calculations ◽  
Structure Calculations

ABSTRACTThe interaction between screw dislocations and [1 1 0] symmetric tilt boundaries is investigated by atomistic calculations. In order to study the differences between fcc and ordered alloys and to study the effect of increasing ordering tendency, many-body potentials representing Cu, Cu3Au and Ni3Al were used. For the ordered alloys, the different possible ordering configurations of the boundaries that were studied are discussed.

High-resolution x-ray analysis of dislocation networks nn tilt boundaries

1988 ◽  
Vol 46 ◽  
pp. 612-613
Author(s):  
J. R. Michael ◽  
C. H. Lin ◽  
S. L. Sass
Keyword(s):  
Grain Boundaries ◽  
Analytical Electron Microscopy ◽  
Solute Segregation ◽  
X Ray ◽  
Periodic Arrays ◽  
Analytical Electron ◽  
Primary Dislocation ◽  
Tilt Boundaries ◽  
Polycrystalline Solids ◽  
Twist Boundaries

The segregation of solute atoms to grain boundaries in polycrystalline solids can be responsible for embrittlement of the grain boundaries. Although Auger electron spectroscopy (AES) and analytical electron microscopy (AEM) have verified the occurrence of solute segregation to grain boundaries, there has been little experimental evidence concerning the distribution of the solute within the plane of the interface. Sickafus and Sass showed that Au segregation causes a change in the primary dislocation structure of small angle [001] twist boundaries in Fe. The bicrystal specimens used in their work, which contain periodic arrays of dislocations to which Au is segregated, provide an excellent opportunity to study the distribution of Au within the boundary by AEM.The thin film Fe-0.8 at% Au bicrystals (composition determined by Rutherford backscattering spectroscopy), ∼60 nm thick, containing [001] twist boundaries were prepared as described previously. The bicrystals were analyzed in a Vacuum Generators HB-501 AEM with a field emission electron source and a Link Analytical windowless x-ray detector.

Atomic Structure and Property Correlation in Pulsed Laser Deposited High -Tc Films

1998 ◽  
Vol 526 ◽  
Author(s):  
R. Kalyanaraman ◽  
S. Oktyabrsky ◽  
K. Jagannadham ◽  
J. Narayan
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Grain Boundaries ◽  
Atomic Structure ◽  
Substrate Surface ◽  
Pulsed Laser ◽  
Structure And Property ◽  
Transmission Electron ◽  
Tilt Boundaries ◽  
Z Contrast

AbstractThe atomic structure of grain boundaries in pulsed laser deposited YBCO/MgO thin films have been studied using transmission electron microscopy. The films have perfect texturing with YBCO(001)//MgO(001), giving rise to low-angle [001] tilt boundaries from the grains with the c-axis normal to substrate surface. Low angle grain boundaries have been found to be aligned preferentially along (100) and (110) interface planes. The energy of (110) boundary planes described by an alternating array of [100] and [010] dislocation is found to be comparable to the energy of a (100) boundary. The existence of these split dislocations is shown to further reduce the theoretical current densities of these boundaries indicating that (110) boundaries carry less current as compared to (100) boundaries of the same misorientation angle. Further, Z-contrast transmission electron microscopy of a 42° asymmetric high-angle grain boundary of YBCO shows evidence for the existence of boundary fragments and a reduced atomic density along the boundary plane

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