Thermodynamic study of nickel-molybdenum and nickel-chromium-molybdenum alloys by using solid oxide electrolytes

Author

Hsien-Lung Tsai

Date of Award

3-1983

Degree Type

Dissertation

Degree Name

Doctor of Philosophy

Major

Metallurgical Engineering

Major Professor

C. R. Brooks

Committee Members

E. E. Stansbury, R. A. Vandermeer, E. S. Clark, W. A. Van Hook

Abstract

The thermodynamic properties of Mo and Cr have been determined in the f. c. c. phase region of Ni-Mo system and the Ni-corner of the Ni-Cr-Mo system, respectively. These properties are derived from the equilibrium electromotive force measurements using solid oxide electrolyte cells of the types: Mo, Mo0₂/Th0₂-Y₂0₃/Mo (binary alloy) , Mo0₂ and Cr , Cr₂0₃/Cr (ternary alloy) , Cr₂0₃ for Ni-Mo binary from 1123 to 1373 K and Ni-Cr-Mo ternary from 1173 to 1373 K, respectively.

In the f. c. c. phase region of Ni-Mo system, from 1123 to 1373 K, the Mo activity presents a positive deviation from ideality. The Mo activity decreases towards ideality as temperature increases.

In the f. c. c. phase region of Ni-Cr-Mo system, from 1173 to 1373 K, the Cr activity increases upon adding Mo into the Ni-Cr-Mo alloy. The Cr activity deviates negatively from ideality below five to ten atomic percent Cr and ten atomic percent Mo and positively above these compositions.

Recommended Citation

Tsai, Hsien-Lung, "Thermodynamic study of nickel-molybdenum and nickel-chromium-molybdenum alloys by using solid oxide electrolytes. " PhD diss., University of Tennessee, 1983.
https://trace.tennessee.edu/utk_graddiss/13151