Constitution and thermodynamics of the Mo-Ru, Mo-Pd, Ru-Pd and Mo-Ru-Pd systems
The constitution of the Mo-Ru, Mo-Pd and Ru-Pd systems was reinvestigated between 800 and 2000°C. The Mo-Ru system is of the eutectic type, a σ-phase Mo 5Ru 3 exists between 1915 and 1143°C. The Mo-Pd system is characterized by an hcp phase Mo 9Pd 11 and by two peritectic reactions, β- Mo( Pd) + L =...
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Published in | Journal of nuclear materials Vol. 167; pp. 49 - 63 |
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Main Author | |
Format | Journal Article |
Language | English |
Published |
Elsevier B.V
01.09.1989
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Online Access | Get full text |
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Summary: | The constitution of the Mo-Ru, Mo-Pd and Ru-Pd systems was reinvestigated between 800 and 2000°C. The Mo-Ru system is of the eutectic type, a σ-phase Mo
5Ru
3 exists between 1915 and 1143°C. The Mo-Pd system is characterized by an hcp phase Mo
9Pd
11 and by two peritectic reactions,
β-
Mo(
Pd) +
L =
Mo
9
Pd
11
and
Mo
9
Pd
11 +
L =
α-
Pd(
Mo). Mo
9Pd
11 decomposes eutectoidally at 1370°C. The Ru-Pd system is simple peritectic. The continuous series of the hcp solid solutions between Mo
9Pd
11 and ϵ-Ru(Mo, Pd) in the ternary Mo-Ru-Pd system observed at 1700°C are suppressed below 1370°C near the Mo-Pd boundary system by the formation of a narrow
α +
β +
ϵ three-phase field. Relative partial molar Gibbs energies of Mo, Mo and Ru in the respective binary systems and of Mo in the ternary system were measured by the EMF method with a Zr(Ca)O
2 electrolyte.
xsΔ
G
̄
Mo
∞
quantities were evaluated at 1200 K which give −43 kJ/mol Mo in Ru and −94 kJ/mol Mo in Pd at infinite dilution. Gibbs energies of formation of the Mo-Ru and Mo-Pd systems were calculated. |
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ISSN: | 0022-3115 1873-4820 |
DOI: | 10.1016/0022-3115(89)90424-8 |