SUPERCONDUCTING PROPERTIES OF PLASTICALLY DEFORMED ALUMINUM

Thesis/Dissertation · Mon Jan 01 04:00:00 EST 1962

OSTI ID:4758390

The sorption of pure hydrogen by high-purity Zr was determined as a function of time by the use of experimental techniques capable of following the reaction to equilibrium at a constant temperature and hydrogen pressure. The Zr was in the form of cylinders and spheres. The experimental hydrogen sorption curves, obtained from Zr which contained 0.3 at.% oxygen in the as-machined condition, agreed with theoretical curves, which were based on Fick's second law and on the assumption that the surface of Zr offered a negligible resistance to hydrogen as compared to the bulk diffusion resistance. The diffusion coefficients for the beta phase of the Zr --H system were calculated from the hydrogen sorption curves. The calculated diffusion coefficients of hydrogen in beta Zr were expressed as: D = 5.32 x 10/sup -3/ exp (--8320/RT) cm/sup 2//sec (760-1010 deg C). The diffusion coefficients for hydrogen were found to be independent of hydrogen concentration in Zr for hydrogen concentrations of up to 41 at.% hydrogen. Further hydrogen sorption experiments were carried out with Zr which contained 1.0, 2.1, and 4.2 at. % oxygen in solid solution with the Zr. A departure from the theoretical hydrogen sorption curves was observed in the form of a decreased rate of hydrogen sorption: the rate decreased with an increased oxygen content in the Zr. However, if the Zr, which contained oxygen, also contained sufficient hydrogen so that the Zr existed in the beta phase, then no effect was observed, and the hydrogen sorption curves agreed with the theoretical curves. This result suggested that the diffusion coefficients for hydrogen in beta Zr were independent of oxygen content in beta Zr in the range of 0.3 to 4.2 at. % oxygen. An investigation was also made of the effect of various surface films on the sorption of hydrogen by Zr, which contained 0.3 at. % oxygen in solid solution. Of the films studied, the chemical film was found to be the most resistant to hydrogen penetration, and the most difficult to remove. (P.C.H.)

• Research Organization: Originating Research Org. not identified
• NSA Number: NSA-17-012707
• OSTI ID: 4758390
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

ALLOTROPY
ALUMINUM
ANNEALING
COLD WORKING
DEFECTS
DEFORMATION
DISLOCATIONS
DRAWING
ELECTRIC CONDUCTIVITY
ELECTRONS
FATIGUE
HYSTERESIS
IMPURITIES
METALS, CERAMICS, AND OTHER MATERIALS
QUANTITATIVE ANALYSIS
RECOVERY
ROLLING
SUPERCONDUCTIVITY
TEMPERATURE
TENSILE PROPERTIES
WIRES