Paper Title:
Numerical Study of Grain Boundary Diffusion in Nanocrystalline Materials
  Abstract

Diffusion in nanocrystalline materials is becoming an increasingly important topic. The analysis of diffusion profiles obtained in nanocrystalline materials with enhanced grain boundary diffusion, however, is not straightforward since assumptions made in the deviation of the conventional models are often not fulfilled. In this contribution numerical diffusion studies are performed in order to investigate effects caused by the high density of interfaces in nanocrystalline material. A continuum model based on the 2D 2-nd Fick’s law was solved by means of the finite element method. This allows us to analyze diffusion profiles for different geometrical situations such as a single boundary, square grains with the grain size of 80 nm and 25 nm and geometries comprising differently oriented boundaries of the average length of 30 nm . The analysis was carried out for different diffusion lengths corresponding to Harrison type A and type B kinetic regimes. For the isolated boundary a very good agreement was achieved in comparison with the classical Whipple’s solution. For nanocrystalline material, however, considerable errors can occur when analyzing the averaged diffusion profiles in the conventional Harrison type A and B kinetics.

  Info
Periodical
Defect and Diffusion Forum (Volumes 237-240)
Edited by
M. Danielewski, R. Filipek, R. Kozubski, W. Kucza, P. Zieba, Z. Zurek
Pages
1043-1048
DOI
10.4028/www.scientific.net/DDF.237-240.1043
Citation
D. Gryaznov, J. Fleig, J. Maier, "Numerical Study of Grain Boundary Diffusion in Nanocrystalline Materials", Defect and Diffusion Forum, Vols. 237-240, pp. 1043-1048, 2005
Online since
April 2005
Export
Price
$32.00
Share

In order to see related information, you need to Login.

In order to see related information, you need to Login.

Authors: Irina V. Belova, Graeme E. Murch
Abstract:In this paper, we show how lattice–based random walks of virtual particles directed by Monte Carlo methods (Lattice Monte Carlo) can be used...
1
Authors: Sergiy V. Divinski, Boris S. Bokstein
Abstract:Some unresolved problems of grain boundary diffusion – restrictions of Fisher-Gibbs model, refinement of the conditions for B- and C-regimes,...
1
Authors: Alain Portavoce, Ivan Blum, Lee Chow, Jean Bernardini, Dominique Mangelinck
Abstract:The measurement of diffusion coefficients in today’s materials is complicated by the down scaling of the studied structures (nanometric...
63