Thermodynamics of the Zr-H system

Journal Article · Fri Dec 01 04:00:00 EST 1995 · Journal of the American Ceramic Society

DOI:https://doi.org/10.1111/j.1151-2916.1995.tb07972.x· OSTI ID:177984

Wang, W E; Olander, D R ^[1]

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1. Lawrence Berkeley Lab., CA (United States)

The consistencies among the reported univariant hydrogen pressures in the three two-phase regions of the Zr-H system, {alpha}Zr/{delta}ZrH{sub 2{minus}x}, {alpha}Zr/{beta}Zr, and {beta}Zr/{delta}ZrH{sub 2{minus}x}, are evaluated with the thermodynamic constraint derived by Speiser. Hydrogen dissolution in {alpha}Zr is evaluated by checking the consistencies among the Sieverts` law constant, the terminal solubility, and the corresponding two-phase univariant pressures involving this phase. A modified Sieverts` law is proposed for the complicated behavior of hydrogen dissolution in {beta}Zr. An analytical composition-temperature-pressure relationship for {delta}ZrH{sub 2{minus}x} is established by using the quasi-chemical model derived by Arita et al. The thermodynamic constraint of the free energy of formation of ZrH{sub 2} shows that the value measured by Fredricken et al. is the most reliable. In addition, a more accurate free energy of formation of zirconium hydride at the upper phase boundary of {alpha}Zr/{delta}ZrH{sub 2{minus}x} two-phase region is suggested.

• Sponsoring Organization: USDOE
• OSTI ID: 177984
• Journal Information: Journal of the American Ceramic Society, Journal Name: Journal of the American Ceramic Society Journal Issue: 12 Vol. 78; ISSN 0002-7820; ISSN JACTAW
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CHEMICAL COMPOSITION
DISSOLUTION
EUTECTOIDS
FORMATION FREE ENERGY
PHASE DIAGRAMS
PRESSURE DEPENDENCE
SOLUBILITY
TEMPERATURE DEPENDENCE
THERMODYNAMIC PROPERTIES
ZIRCONIUM HYDRIDES