Calorimetrically measured enthalpies for the reaction of H[sub 2] (g) with Zr and Zr alloys

Journal Article · Thu Jul 01 04:00:00 EDT 1993 · Metallurgical Transactions, A (Physical Metallurgy and Materials Science); (United States)

DOI:https://doi.org/10.1007/BF02646588· OSTI ID:6239568

Dantzer, P ^[1]; Luo, W ^[2]; Flanagan, T B; Clewley, J D ^[3]

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1. CNRS-URA, Orsay (France)
2. Brookhaven National Lab., Upton, NY (United States). Dept. of Applied Science
3. Univ. of Vermont, Burlington, VT (United States)

The enthalpy for the direct reaction of H[sub 2] (g) with Zr has been measured by calorimetry at moderate, 323 K, and elevated, 928 K, temperatures over a large range of H contents. The elevated temperature enthalpies were determined for solution in the [alpha] phase, for the ([alpha] + [beta]) phases, the [beta] phase, the ([beta] + [gamma]) phases, and the [gamma] phase. Simultaneously, the equilibrium pressures were measured. A combination of [Delta]G[sub H] = 1/2RT ln p[sub H[sub 2]], values and the enthalpies gives the corresponding entropies. At 323 K, where equilibrium pressures cannot be measured, the enthalpy for the reaction 1/2H[sub 2] (g) + Zr/1.5 [r arrow] ZrH[sub 1.5]/1.5 was determined as [minus]87 [plus minus] 1.5 kJ/mol H. The enthalpy for reaction of H[sub 2] (g) and Zr (2.5 wt pct Nb) has been determined calorimetrically at 323 K and is found to decrease in exothermicity from [minus]86 to [minus]78 kJ/mol H in the range of (H/Zr) values from 0 to 1.5. Enthalpies of reaction were also measured at the same temperature for a two-phase alloy consisting of Zr-rich and Zr[sub 2]Ni phases with an overall stoichiometry of Zr[sub 0.85]Ni[sub 0.15].

• OSTI ID: 6239568
• Journal Information: Metallurgical Transactions, A (Physical Metallurgy and Materials Science); (United States), Journal Name: Metallurgical Transactions, A (Physical Metallurgy and Materials Science); (United States) Vol. 24:7; ISSN 0360-2133; ISSN MTTABN
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360105* -- Metals & Alloys-- Corrosion & Erosion
ALLOYS
CALORIMETRY
CANDU TYPE REACTORS
CHEMICAL REACTIONS
DATA
ELEMENTS
EMBRITTLEMENT
ENTHALPY
ENTROPY
EXPERIMENTAL DATA
HEAVY WATER MODERATED REACTORS
HYDRIDATION
HYDROGEN
HYDROGEN EMBRITTLEMENT
INFORMATION
METALS
NICKEL ALLOYS
NIOBIUM ALLOYS
NONMETALS
NUMERICAL DATA
PHASE STUDIES
PHYSICAL PROPERTIES
PRESSURE TUBE REACTORS
REACTION HEAT
REACTORS
THERMAL REACTORS
THERMODYNAMIC PROPERTIES
TRANSITION ELEMENTS
ZIRCONIUM
ZIRCONIUM ALLOYS
ZIRCONIUM BASE ALLOYS