Composition and Pressure Dependence of the Diffusion Coefficients in Binary Liquid Alloys

Dezső L. Beke

doi:10.4028/www.scientific.net/DDF.297-301.1371

Paper Titles

Diffusion in SC Ni-Base Superalloy under Viscoplastic Deformation
p.1340

Diffusion Phenomena of the Oxygen and Nitrogen in Niobium by Mechanical Spectroscopy
p.1346

Effect of Reactive Elements and Microstructure of Steel on High Temperature Oxidation Behaviour of Ferritic Stainless Steels
p.1354

On the Grain-Boundary Diffusion in Polycrystalline Materials and Thin Films
p.1362

Composition and Pressure Dependence of the Diffusion Coefficients in Binary Liquid Alloys
p.1371

Diffusion in Binary Silicides of Iron and Molybdenum
p.1377

Air Oxidation Behaviour of a Ti-6Al-7Nb Alloy
p.1389

The Effect of Oxidation on The Structure and Hardness of (Zr, Hf)N Coatings
p.1395

Molecular Dynamics Calculations of InSb Thermal Conductivity
p.1400

HomeDefect and Diffusion ForumDefect and Diffusion Forum Vols. 297-301Composition and Pressure Dependence of the...

Composition and Pressure Dependence of the Diffusion Coefficients in Binary Liquid Alloys

Abstract:

There are a number of well-known empirical relations for diffusion in solids. For example the proportionality between the self-diffusion activation energy and melting point or between the entropy of the diffusion and the ratio of activation energy and the melting point (Zener rule) are perhaps the best known ‘rules of thumb’. We have shown earlier in our Laboratory, that these relations are direct consequences of the similarity of interatomic potentials seen by ions in solids. On the basis of this, similar relations were extended for impurity and self diffusion in binary solid alloys. In this paper, results for binary liquid mixtures will be reviewed. First a minimum derivation of the temperature dependence of the self-diffusion coefficient, D, is presented (minimum derivation in the sense that it states only that the reduced (dimensionless) D should be a universal function of the reduced temperature), using the similarity of interatomic potentials and dimensional analysis. Then the extension of this relation for determination of the pressure and composition dependence of the self-diffusion coefficients is described using pressure and composition dependent scaling parameters (melting point, atomic volume and mass). The obtained universal form (valid for binary liquid alloys) is very useful for the estimation of the temperature, composition and pressure dependence of the self-diffusion coefficients. Finally, the relation for the ratio of the impurity and self-diffusion coefficients is derived.