Atomistic theory and computer simulation of grain boundary structure and diffusion

2000 ◽  
Vol 12 (42) ◽  
pp. R497-R516 ◽  
Author(s):  
Diana Farkas
Keyword(s):  
Computer Simulation ◽  
Grain Boundary ◽  
Boundary Structure ◽  
Grain Boundary Structure ◽  
And Diffusion

Grain Boundary Structure and Diffusion Induced Grain Boundary Migration

1991 ◽  
Vol 229 ◽  
Author(s):  
A. H. King
Keyword(s):  
Grain Boundary ◽  
Grain Boundaries ◽  
Boundary Migration ◽  
Structural Models ◽  
Solute Concentration ◽  
Boundary Structure ◽  
Grain Boundary Migration ◽  
Grain Boundary Structure ◽  
And Diffusion

AbstractWe present a review of systematic studies of diffusion induced grain boundary migration (DIGM). The results are compared with structural models for the grain boundaries in order to assess the effects of structure upon DIGM. The nucleation of DIGM is also assessed in the light of grain boundary structure and it is demonstrated that changes of grain boundary solute concentration can induce large enough energy changes to drive novel grain boundary dissociation reactions.

Atomistic Simulation of Grain Boundary Structure and Diffusion in B2 NiAl

1996 ◽  
Vol 458 ◽  
Author(s):  
Yuri Mishin ◽  
Diana Farkas
Keyword(s):  
Grain Boundary ◽  
Atomistic Simulation ◽  
Effective Activation Energy ◽  
Correlation Effect ◽  
Boundary Structure ◽  
Self Diffusion ◽  
Embedded Atom ◽  
Grain Boundary Structure ◽  
And Diffusion

ABSTRACTUsing embedded atom potentials and molecular statics we calculate the structure and energy of [001] tilt grain boundaries in NiAl for 25 orientations with Σ values from 5 to 185. For three structures (stoichiometric, Ni-rich and Al-rich) of the Σ = 5 (210) boundary we simulate tracer self-diffusion by the vacancy mechanism both parallel and perpendicular to the tilt axis using the Monte Carlo technique. The effective activation energy calculated in a wide temperature range is compared with the spectrum of individual jump energies in the boundary core. The results are interpreted in terms of the grain boundary structure-diffusion relationship and the role of the jump correlation effect in grain boundary diffusion.

On The Study Of Grain Boundary Segregation Using X-Ray Diffraction And Computer Simulation

1991 ◽  
Vol 238 ◽  
Author(s):  
C. A. Counterman ◽  
I. Majid ◽  
P. D. Bristowe ◽  
R. W. Balluffi
Keyword(s):  
Computer Simulation ◽  
Grain Boundary ◽  
Boundary Segregation ◽  
Grain Boundary Segregation ◽  
Boundary Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Grain Boundary Structure ◽  
Structure Factors ◽  
Diffraction Effects

ABSTRACTThe possibility of studying grain boundary segregation using X-ray diffraction is explored by performing a computer simulation of the diffraction effects expected from the segregation of solute atoms to grain boundaries in two gold alloy systems, i.e. Au-Ag and Au-Ni. Using atomistic Monte-Carlo and molecular statics methods, equilibrium boundary structures are determined and analyzed by computing the grain boundary structure factors. Various changes in both relative and absolute grain boundary structure factors are found which can be directly related to structural and compositional changes due to segregation. In addition, systematic diffraction effects are found as a function of boundary misorientation. The experimental conditions required for verifying these predictions are discussed.

Two Investigations into Grain Boundary Structure

1977 ◽  
Vol 35 ◽  
pp. 688-691
Author(s):  
P. Humble
Keyword(s):  
Grain Boundary ◽  
Dark Field ◽  
Boundary Structure ◽  
Boundary Dislocation ◽  
Bright Field ◽  
Intrinsic Structure ◽  
Weak Beam ◽  
Grain Boundary Structure ◽  
Independent Information ◽  
Diffraction Patterns

There has been sustained interest over the last few years into both the intrinsic (primary and secondary) structure of grain boundaries and the extrinsic structure e.g. the interaction of matrix dislocations with the boundary. Most of the investigations carried out by electron microscopy have involved only the use of information contained in the transmitted image (bright field, dark field, weak beam etc.). Whilst these imaging modes are appropriate to the cases of relatively coarse intrinsic or extrinsic grain boundary dislocation structures, it is apparent that in principle (and indeed in practice, e.g. (1)-(3)) the diffraction patterns from the boundary can give extra independent information about the fine scale periodic intrinsic structure of the boundary.In this paper I shall describe one investigation into each type of structure using the appropriate method of obtaining the necessary information which has been carried out recently at Tribophysics.

Relationships Between Grain Boundary Structure and Material Properties

1980 ◽  
Vol 38 ◽  
pp. 366-369
Author(s):  
Brian Ralph ◽  
Barlow Claire ◽  
Nicola Ecob
Keyword(s):  
Grain Boundary ◽  
Material Properties ◽  
Main Property ◽  
Grain Structure ◽  
Boundary Structure ◽  
Grain Boundary Structure ◽  
Property Changes

This brief review seeks to summarize some of the main property changes which may be induced by altering the grain structure of materials. Where appropriate an interpretation is given of these changes in terms of current theories of grain boundary structure, and some examples from current studies are presented at the end of this paper.

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