An Expansion of the Fisher Model for Concentration Dependent Grain Boundary Diffusion

The problem of grain boundary diffusion for a case of boundary grain with periodic heterogeneity diffusion properties is considered. Dependence of Laplace transform images of impurity concentration on various diffusion conductivity places is built. The dimensionless parameters, forming the system of grain boundary diffusion regimes are determined. The space (ln x,lnt,1/T) is divided into areas in which the ratio ln ln ~ ln ln ( / ) ln eff o C r x−k t− Q RT − A is maintained, when the parameters of diffusion regime are constant. The values of parameters , , , eff o r k Q A fully specify the diffusion regimes. On this base the new concept for the definition of grain boundary diffusion regimes is carried out and the method for construction of simplified tracer concentration profile is proposed.

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Reactionary Interaction as the Basis of Occurrence Heterogeneity Diffusion Properties Grain Boundaries in Polycrystalline Silver

Defect and Diffusion Forum ◽

10.4028/www.scientific.net/ddf.277.221 ◽

2008 ◽

Vol 277 ◽

pp. 221-226

Author(s):

Valerie M. Koloskov ◽

V.L. Gapontsev

Keyword(s):

Grain Boundary ◽

Data Processing ◽

Grain Boundaries ◽

Boundary Diffusion ◽

Grain Boundary Diffusion ◽

Primary Data ◽

Tail Part ◽

Fisher Model ◽

Polycrystalline Silver ◽

Diffusion Properties

The new way of calculation of segregation enthalpy on the basis of grain boundary diffusion data is offered. It proceeds from the primary data on an interval "B"- regime of grain boundary diffusion. For data processing we used the expression for coefficient of grain boundary diffusion got by Borisov and Lubov according to Fisher model for a tail part of the concentration curve. To approve this approach the data of tellurium diffusion in grain boundary of polycrystalline silver are considered.

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Investigation of Grain-Boundary Diffusion of Co in Mo by Radiotracer Method and Mössbauer Spectroscopy

Defect and Diffusion Forum ◽

10.4028/www.scientific.net/ddf.363.21 ◽

2015 ◽

Vol 363 ◽

pp. 21-26 ◽

Cited By ~ 2

Author(s):

Vladimir V. Popov ◽

A.V. Sergeev ◽

A.Yu. Istomina

Keyword(s):

Grain Boundary ◽

Boundary Diffusion ◽

Grain Boundary Diffusion ◽

Experimental Results ◽

Radiotracer Method ◽

Fisher Model ◽

Temperature Dependences ◽

Boundary Diffusivity

Grain boundary diffusion of Co in Mo has been studied by radiotracer analysis and emission Mössbauer spectroscopy. The experimental results are treated based on the specified Fisher model. The mechanism of grain boundary diffusion of Co in Mo and temperature dependences of segregation factor and grain boundary diffusivity have been determined.

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Determination of Grain Boundary Diffusion Parameters Based on Specified Model of Grain Boundary Diffusion and Combined Analysis of Radiotracer and Mössbauer Spectroscopy Data

Diffusion Foundations ◽

10.4028/www.scientific.net/df.5.21 ◽

2015 ◽

Vol 5 ◽

pp. 21-39 ◽

Cited By ~ 1

Author(s):

Vladimir V. Popov ◽

A.V. Sergeev

Keyword(s):

Grain Boundary ◽

Boundary Diffusion ◽

Grain Boundary Diffusion ◽

Model Specification ◽

Radiotracer Technique ◽

Combined Analysis ◽

Additional Information ◽

Diffusion Parameters ◽

Fisher Model

The classical Fisher model of grain-boundary diffusion and the traditional method of determination of grain-boundary diffusion parameters by radiotracer technique combined with the serial-sectioning method are analyzed. The Fisher model specification based on the data of the emission Mössbauer spectroscopy is considered, and the additional information which can be extracted from the Mössbauer studies is discussed. The possibility of determination of grain-boundary diffusion parameters based on the combined analysis of the radiotracer technique and Mössbauer spectroscopy with the application of the specified Fisher model of grain-boundary diffusion is considered. This approach is demonstrated by an example of determination of grain-boundary diffusion of Co in W and Mo.

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Diffusion at Short Circuits: State of the Art

Defect and Diffusion Forum ◽

10.4028/www.scientific.net/ddf.297-301.1267 ◽

2010 ◽

Vol 297-301 ◽

pp. 1267-1283 ◽

Cited By ~ 5

Author(s):

Boris S. Bokstein

Keyword(s):

Solid State ◽

Grain Boundary ◽

Boundary Diffusion ◽

Boundary Segregation ◽

Grain Boundary Diffusion ◽

Polycrystalline Materials ◽

Solid State Diffusion ◽

Diffusion Parameters ◽

State Diffusion ◽

Fisher Model

Evidence for solid-state diffusion (the second half of the 19th century). The first measurements of solid state diffusion (W. Roberts-Austen, 1896–1922). The first tracer experiments to determine the solid-state diffusion (G. von Hevesy, 1913–1923). The first evidence of accelerated diffusion in polycrystalline materials (1924–1935). Autoradiographic studies of grain boundary diffusion (50s of 20th century). The first quantitative experimental and theoretical studies of the “short circuiting” diffusion (beginning from 1949, D. Turnbull and R. Hoffman – General Electric Research Lab.): radiotracer serial sectioning method, the Fisher model (1951) for grain boundary diffusion, exact solutions and developments of the Fisher model (1954–1963). The progress in the experimental methods for determination of grain boundary diffusion data and results of measurements for different metallic systems (up to date). The measurements of grain boundary diffusion parameters in the B and C regimes. Grain boundary diffusion and grain boundary segregation. Nonlinear segregation effects. Structural effects of grain boundary diffusion. Diffusion in bicrystals. Diffusion in nanocrystals. Computer simulation of grain boundary diffusion. Mechanisms of grain boundary diffusion.

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