Vacancy thermodynamics for intermediate phases using the compound energy formalism

被引：16

作者：

Oates, W. A. ^{[1
]}

Chen, S. -L. ^{[2
]}

Cao, W. ^{[2
]}

Zhang, F. ^{[2
]}

Chang, Y. A. ^{[3
]}

Bencze, L. ^{[4
]}

Doernberg, E. ^{[5
]}

Schmid-Fetzer, R. ^{[5
]}

机构：

[1] Univ Salford, Inst Mat Res, Salford M5 4WT, Lancs, England

[2] CamuTherm LLC, Madison, WI 53719 USA

[3] Univ Wisconsin, Dept Mat Sci & Engn, Madison, WI 53706 USA

[4] Eotvos Lorand Univ, Dept Phys Chem, H-1117 Budapest, Hungary

[5] Tech Univ Clausthal, Inst Met, D-38678 Clausthal Zellerfeld, Germany

来源：

ACTA MATERIALIA | 2008年 / 56卷 / 18期

关键词：

Vacancies; Compound energy formalism; Thermodynamics; Chemical potential; Intermetallic compounds;

D O I：

10.1016/j.actamat.2008.07.002

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

The compound energy formalism is widely used for thermodynamic descriptions of intermediate phases containing vacancies. For a two-sublattice model, represented by (A, B, Va)(0.5) : (A, B, Va)(0.5), it is physically necessary to take the reference state Gibbs energy of the pure vacancy end member, G(Va:Va)(o), as zero, irrespective of temperature, pressure, or the chemical composition and Structure of the actual intermediate phase containing the vacancies. This assumption leads to more than one possible Solution for the calculated value of the equilibrium vacancy concentration. The assumption can be avoided if the compound end members Lire regarded as Cluster Solution members and an ideal dilute solution reference state is used for the vacancy Clusters. In this case, G(Va:Va)(o) does depend on the host as well as on temperature and pressure. An analysis of the thermodynamic properties of the B2 phase in the Al-Ni system is used as a demonstration of this alternative view. (C) 2008 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

引用

页码：5255 / 5262

页数：8

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