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Phase stability in Be-Nb and Be-Nb-Zr intermetallics

Description: Sputter deposition of Be-Nb alloys at low temperature (30{degrees}C) produces an amorphous phase for compositions >5 at.% Nb. A metastable crystalline phase which can be considered a highly faulted form of the Be{sub 12}Nb occurs at higher deposition temperatures or by low-temperature annealing of the amorphous phase. Because of structural similarities, this metastable phase is a precursor to the formation of either Be{sub 12}Nb or Be{sub 17}Nb{sub 2} upon high temperature annealing. There was … more
Date: September 1, 1991
Creator: Brimhall, J.L.; Charlot, L.A. & Bruemmer, S.M.
Partner: UNT Libraries Government Documents Department
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Radiation damage studies in CTR materials using dual-beam irradiation

Description: A dual beam, ion irradiation facility for studying radiation damage problems applicable to fusion first walls has been described. Experiments on molybdenum have shown that co-implanted helium can alter the internal void microstructure during heavy ion irradiation but does not appreciably change the total swelling. Heavy ion irradiation of a Nb-1 Zr alloy have shown that irradiation can induce precipitate formation and that existing precipitates can influence the damage microstructure.
Date: January 1, 1980
Creator: Brimhall, J.L.
Partner: UNT Libraries Government Documents Department
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Metastable phase formation in Be-Nb intermetallic compounds

Description: Amorphous structures or metastable crystalline phases are produced in sputter-deposited Beryllium-Niobium (Be-Nb) alloys (5-15 at. % Nb) depending on the substrate temperature. The metastable phases transform to the stable Be{sub 12}Nb, Be{sub 17}Nb{sub 2}Nb phases on annealing at temperatures >800{degree}C. No Be{sub 5}Nb phase was found and the Be{sub 17}Nb{sub 2} phase is stable to low temperature. The Be{sub 12}Nb phase appeared to have a stoichiometric range of about 5.5 to 7.7 at. % Nb. T… more
Date: November 1, 1990
Creator: Brimhall, J.L.; Charlot, L.A. & Bruemmer, S.M.
Partner: UNT Libraries Government Documents Department
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Effect of pulsed irradiation on void swelling in nickel

Description: This study has compared the void microstructure in nickel induced by a pulsed ion bombardment to that induced by a steady-state irradiation. Pulse cycles of 10 seconds on and 10 seconds off produced no measurable difference in the void growth and swelling in the temperature range 775 to 975/sup 0/K compared to continuous irradiation at the same instantaneous dose rate. Void annealing during the pulse annealing period was minimal due to the large void sizes which were obtained in these irradiati… more
Date: July 1, 1981
Creator: Brimhall, J. L.; Charlot, L. A. & Simonen, E. P.
Partner: UNT Libraries Government Documents Department
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Radiation hardening effects on localized deformation and stress corrosion cracking of stainless steels

Description: Radiation hardening in austenitic stainless steels modifies deformation characteristics and correlate well with increased susceptibility to intergranular stress corrosion cracking (IGSCC). Available data on neutron-irradiated materials have been analyzed and correlations developed between fluence, yield strength, and cracking susceptibility in high-temperature water environments. Large heat-to-heat differences in critical fluence (0.2 to 2.5 {times} 10{sup 21} n/cm{sup 2}) for IGSCC are documen… more
Date: August 1, 1993
Creator: Bruemmer, S. M.; Cole, J. I.; Brimhall, J. L.; Carter, R. D. & Was, G. S.
Partner: UNT Libraries Government Documents Department
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Issues related to the transport of a transportable storage cask after storage

Description: An evaluation was performed to assess whether the reliability of a transportable storage cask system and the risks associated with its use are comparable to those associated with existing transport cask systems and, if they are not, determine how the transportable storage cask system can be made as reliable as existing systems. Reliability and failure mode analyses of both transport-only casks and transportable storage casks and implementation options are compared. Current knowledge regarding t… more
Date: December 31, 1991
Creator: McConnell, P.; Brimhall, J. L.; Creer, J. M.; Gilbert, E. R.; Sanders, T. L. & Jones, R. H.
Partner: UNT Libraries Government Documents Department
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Computing the time dependence of void size distributions during irradiation and annealing

Description: The response of particle size distributions to annealing is described analytically by the Wagner--Lifshitz--Slyosov theory of coarsening. Although the theory has been used to predict void annealing kinetics in irradiated materials, the limits of the model prevent a complete interpretation of the rate controlling mechanisms. These limits are overcome with a numerical solution to the problem for the combined influences of volume diffusion, surface kinetics, and irradiation-induced point defects. … more
Date: January 1, 1976
Creator: Simonen, E. P. & Brimhall, J. L.
Partner: UNT Libraries Government Documents Department
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Summary report of BCC ion correlation experiment. [800 to 1000/sup 0/C; voids; swelling; Ni/sup 2//sup+/, Mo/sup+/, Cu/sup 4//sup+/, and H/sup+/ ions]

Description: An interlaboratory program was established to compare the radiation damage produced in Mo at 800 to 1000/sup 0/C by different ions of different energies. The program included comparisons of microstructures produced by different ions, of measurements on a round robin TEM specimen, and of measurements on a common micrograph. Results are discussed. Ions used included Ni/sup 2 +/, Mo/sup +/, Cu/sup 4 +/, and H/sup +/.
Date: August 17, 1976
Creator: Brimhall, J L
Partner: UNT Libraries Government Documents Department
open access

Deformation mechanisms in Be{sub 12}X compounds

Description: Dislocation structures have been examined, and active slip systems identified, in Be{sub l2}Nb after compressive deformation at 20, 800, 900 1000 and 1200C. A large number of slip systems are active at 1200C, but these decrease significantly at temperatures below 1000C. Dislocation structures at low temperatures are limited to 1/2<101(101) partial dislocations either paired or creating isolated planar faults. Significant ductility is not observed until 1200C when a second type of partial disloc… more
Date: December 1, 1992
Creator: Bruemmer, S. M.; Brimhall, J. L.; Charlot, L. A.; Sondhi, S.; Hoagland, R. G. & Hirth, J. P.
Partner: UNT Libraries Government Documents Department
open access

Synthesis and properties of nanostructures formed by sputter deposition

Description: Nanoscale grain structures can be created in many materials by high rate sputter deposition upon an appropriate substrate. By controlling the sputtering parameters of substrate temperature, deposition rate, and substrate bias, the scale of microstructure can vary from amorphous to grain sizes typical of conventionally treated material. The morphology and size of the microstructure will also be controlled by post-deposition heat treatment, particularly in the heat treatment of amorphous and meta… more
Date: January 1, 1991
Creator: Brimhall, J.L.; Henager, C.H. Jr.; Merz, M.D. & Bruemmer, S.M.
Partner: UNT Libraries Government Documents Department
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Temperature and strain-rate effects on deformation mechanisms in irradiated stainless steel

Description: Analysis of the deformation microstructures in ion-irradiated stainless steel shows twinning to be the predominant deformation mode at room temperature. Dislocation channelling also occurs under slow strain rate conditions. Stresses required for twinning were calculated by the model of Venables and are compatible with observed yield stresses in neutron-irradiated material if loops are the principal twin source. Computation of the expected radiation hardening from the defect structure, based on … more
Date: November 1, 1994
Creator: Brimhall, J. L.; Cole, J. I.; Vetrano, J. S. & Bruemmer, S. M.
Partner: UNT Libraries Government Documents Department
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Tritium permeation and related studies on barrier treated 316 stainless steel

Description: To verify the performance of permeation-resistant cladding for tritium targets designed for a New Production Reactor Light Water Reactor, a tritium test facility was designed, developed, and certified. Testing is ongoing to verify the performance of reference designed targets. Accurate measurements were taken of tritium permeating from barrier-coated cladding specimens immersed in high-temperature autoclaves configured to simulate reactor coolant conditions. The tritium test pressure is control… more
Date: September 1, 1991
Creator: Gilbert, E. R.; Allen, R. P.; Baldwin, D. L.; Bell, R. D.; Brimhall, J. L.; Clemmer, R. G. et al.
Partner: UNT Libraries Government Documents Department
open access

Properties and potential of high-temperature niobium beryllides

Description: Recent research on the low- and high-temperature properties of two beryllium-niobium intermetallic compounds, Be{sub l2}Nb and Be{sub l7}Nb{sub 2}, is reviewed and discussed. Strength (bend and compression), hardness and fracture toughness has been mapped as a function of test temperature up to 1200C. Results for hot-isostatically-pressed Be{sub 12}Nb and Be{sub l7}Nb{sub 2} are highlighted illustrating the potential for reasonable strength at both low and high temperatures. Limitations for str… more
Date: December 1, 1992
Creator: Bruemmer, S. M.; Brimhall, J. L.; Henager, C. H. Jr. & Hirth, J. P.
Partner: UNT Libraries Government Documents Department
open access

Effect of helium on void swelling in vanadium

Description: Little difference in void microstructural swelling of vanadium is observed when helium is injected simultaneously with a 46- or 5-MeV nickel beam as compared to no helium injection, at least at high dose rates. At lower dose rates, a strong helium effect is seen when the helium is injected prior to heavy ion bombardment. The effect of the helium is shown to be a strong function of the overall displacement damage rate. (DLC)
Date: January 1, 1975
Creator: Brimhall, J. L. & Simonen, E. P.
Partner: UNT Libraries Government Documents Department
open access

Deformation mechanisms in Be[sub 12]X compounds. [X = Nb]

Description: Dislocation structures have been examined, and active slip systems identified, in Be[sub l2]Nb after compressive deformation at 20, 800, 900 1000 and 1200C. A large number of slip systems are active at 1200C, but these decrease significantly at temperatures below 1000C. Dislocation structures at low temperatures are limited to 1/2<101(101) partial dislocations either paired or creating isolated planar faults. Significant ductility is not observed until 1200C when a second type of partial disloc… more
Date: December 1, 1992
Creator: Bruemmer, S. M.; Brimhall, J. L.; Charlot, L. A.; Sondhi, S.; Hoagland, R. G. & Hirth, J. P.
Partner: UNT Libraries Government Documents Department
open access

Radiation-induced segregation in candidate fusion-reactor alloys

Description: The effect of radiation on surface segregation of minor and impurity elements has been studied in four candidate fusion reactor alloys. Radiation induced surface segregation of phosphorus was found in both 316 type stainless steel and in Nimonic PE-16. Segregation and depletion of the other alloying elements in 316 stainless steel agreed with that reported by other investigators. Segregation of nitrogen in ferritic HT-9 was enhanced by radiation but no phosphorus segregation was detected. No si… more
Date: July 1, 1981
Creator: Brimhall, J. L.; Baer, D. R. & Jones, R. H.
Partner: UNT Libraries Government Documents Department
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