243 Matching Results

Search Results

Advanced search parameters have been applied.

in subjects: "Metallurgical Effects"

open access

The Effect of H and He on Irradiation Performance of Fe and Ferritic Alloys

This research program was designed to look at basic radiation damage and effects and mechanical properties in Fe and ferritic alloys. The program scope included a number of materials ranging from pure single crystal Fe to more complex Fe-Cr-C alloys. The range of materials was designed to examine materials response and performance on ideal/model systems and gradually move to more complex systems. The experimental program was coordinated with a modeling effort. The use of pure and model alloys a… more

Date: January 22, 2010

Creator: Stubbins, James F.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Dynamic shear deformation in high purity Fe

The forced shear test specimen, first developed by Meyer et al. [Meyer L. et al., Critical Adiabatic Shear Strength of Low Alloyed Steel Under Compressive Loading, Metallurgical Applications of Shock Wave and High Strain Rate Phenomena (Marcel Decker, 1986), 657; Hartmann K. et al., Metallurgical Effects on Impact Loaded Materials, Shock Waves and High Strain rate Phenomena in Metals (Plenum, 1981), 325-337.], has been utilized in a number of studies. While the geometry of this specimen does no… more

Date: January 1, 2009

Creator: Cerreta, Ellen K; Bingert, John F; Trujillo, Carl P; Lopez, Mike F & Gray, George T

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Atomic-volume variations of (alpha)-Pu alloyed with Al, Ga, and Am from first-principles theory

First-principles methods are employed to calculate the ground-state atomic densities (or volumes) of {alpha}-Pu alloyed with Al, Ga, and Am. Three configurations for the alloying atom are considered. (1) It is located at the most open and energetically most favorably site. (2) It is located in the least open site. (3) It is randomly distributed within the {alpha}-Pu matrix. When alloyed with Al or Ga, {alpha}-Pu behaves similarly, it expands considerably for configurations (2) and (3), while fo… more

Date: January 9, 2007

Creator: Soderlind, P; Landa, A & Wolfer, W G

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Raman Studies of Nanocrystalline CdS:O Film

Oxygenated nanocrystalline CdS films show improved solar cell performance, but the physics and mechanism underlying this are not yet clearly understood. Raman study provides complementary information to the understanding obtained from other experimental investigations. A comprehensive analysis of the existing experimental data (including x-ray diffraction, transmission, transmission electron microscopy, and Raman) has led to the following conclusions: (1) The O-incorporation forms CdS1-xOx allo… more

Date: January 1, 2005

Creator: Zhang, Y.; Wu, X.; Dhere, R.; Zhou, J.; Yan, Y. & Mascarenhas, A.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

An Atomistic Modeling Study of Alloying Element Impurity Element, and Transmutation Products on the Cohesion of a Nickel e5 {l_brace}001{r_brace} Twist Grain Boundary

Atomistic modeling methods were employed to investigate the effects of impurity elements on the metallurgy, irradiation embrittlement, and environmentally assisted cracking of nickel-base alloys exposed to nuclear environments. Calculations were performed via ab initio atomistic modeling methods to ensure the accuracy and reliability of the results. A Griffith-type fracture criterion was used to quantitatively assess the effect of elements or element pairs on the grain boundary cohesive strengt… more

Date: June 16, 2003

Creator: Jr., G.A. Young; Najafabadi, R.; Strohmayer, W.; Baldrey, D. G.; Hamm, B.; Harris, J. et al.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Final Report

In this program the teams at Penn State University (PSU), Sandia National Laboratories (SNL), DCH Technology (DCHT), and Air Products and Chemicals Inc. (APCI), have aggressively pursued engineering solutions to eliminate barriers to solid-state chemiresistor hydrogen sensor technology. The metallurgical effects of alloying palladium with nickel have been shown to prevent phase transitions in the thin films at high H2 overpressures, making the devices more suitable for IOF process conditions. W… more

Date: May 23, 2003

Creator: Horn, Mark W.; McDaniel, Anthony & Schweighardt, Frank K.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Mesoporous catalysts, supports and catalytic membranes based on MCM-41. Final report for the period January 15,2000 - January 14, 2001

The research had two objectives: to understand the effect of pore size on the chemistry and activity of active sites, and to investigate both the pore size and anchoring effect of Me-MCM-41 on Pt clusters (where Me is a metal incorporated in silica-based MCM-41). The focus is not on the effect of pore size on transport of reactants and products, but on how the local radius of curvature might affect the properties of a foreign ion embedded in a silicon wall that acts as a catalytic site or ancho… more

Date: July 1, 2001

Creator: Haller, Gary L.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Influence of Mg and In on defect formation in GaN; bulk and MOCVD grown samples

Transmission electron microscopy studies were applied to study GaN crystals doped with Mg. Both: bulk GaN:Mg crystals grown by a high pressure and high temperature process and those grown by metal-organic chemical-vapor deposition (MOCVD) have been studied. Structural dependence on growth polarity was observed in the bulk crystals. Spontaneous ordering (formation of polytypoids) was observed for growth in the N to Ga polar direction (N polarity). On the opposite site of the crystal (growth in t… more

Date: November 22, 2000

Creator: Liliental-Weber, Z.; Benamara, M.; Jasinski, J.; Swider, W.; Washburn, J.; Grzegory, I. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Fabrication technology for ODS Alloy MA957

A successful fabrication schedule has been developed at Carpenter Technology Corporation for the production of MA957 fuel and blanket cladding. Difficulties with gun drilling, plug drawing and recrystallization were overcome to produce a pilot lot of tubing. This report documents the fabrication efforts of two qualified vendors and the support studies performed at WHC to develop the fabrication-schedule.

Date: March 16, 2000

Creator: Hamilton, ML; Gelles, DS; Lobsinger, RJ; Paxton, MM & Brown, WF

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Manufacturing of nickel-base superalloys with improved high-temperature performance

This report summarizes the results of research conducted as part of CRADA ORNL95-0327 between Oak Ridge National Laboratory and Teledyne Allvac (now Allvac, an Allegheny Teledyne Co.). The objective was to gain a better understanding of the role of trace elements in nickel-based superalloys, with the ultimate goal of enhancing performance without significantly increasing production cost. Two model superalloys, IN 718 and Waspaloy, were selected for this study, and the synergistic effects of P a… more

Date: January 1, 2000

Creator: McKamey, C. G.; George, E. P.; Liu, C. T.; Horton, J. A.; Carmichael, C. A.; Kennedy, R. L. et al.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

THE INFLUENCE OF NANOENGINEERED Cu DEFECTS ON ALUMINUM PITTING INITIATION

Nanoengineering technologies have been used to generate well defined arrays of pure Cu islands within an Al thin film matrix in order to examine the impact of noble particle defects on the initiation of metastable pitting. The Cu particles form local galvanic cells with the surrounding Al matrix and drive metastable corrosion. Electrical isolation of the Cu particles from the Al occurs due to selective Al dissolution and appears to correlate to cessation of metastable events. Distributions of p… more

Date: November 1, 1999

Creator: Wall, F. D.; Son, K. A.; Missert, N. A.; Barbour, J. C.; Martinez, M. A.; Zavidil, K. R. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

The effect of actinides on the microstructural development in a metallic high-level nuclear waste form

Waste forms to contain material residual from an electrometallurgical treatment of spent nuclear fuel have been developed by Argonne National Laboratory. One of these waste forms contains waste stainless steel (SS), fission products that are noble to the process (e.g., Tc, Ru, Pd, Rh), Zr, and actinides. The baseline composition of this metallic waste form is SS-15wt.% Zr. The metallurgy of this baseline alloy has been well characterized. On the other hand, the effects of actinides on the alloy… more

Date: October 25, 1999

Creator: Keiser, D. D. Jr.; Sinkler, W.; Abraham, D. P.; Richardson, J. W., Jr. & McDeavitt, S. M.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Evaluation of oxide dispersion strengthened (ODS) molybdenum and molybdenum-rhenium Alloys

Oxide dispersion strengthened (ODS) molybdenum alloys being developed for high temperature applications possess excellent high temperature strength and creep resistance. In addition they exhibit a ductile-to-brittle transition temperature (DBIT) in the worked and stress-relieved condition under longitudinal tensile load well below room temperature. However, in the recrystallized condition, the DBTT maybe near or above room temperature, depending on the volume fraction of oxide dispersion and th… more

Date: October 22, 1999

Creator: Mueller, A.J.; Bianco, R. & Buckman, R.W. Jr.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

The embrittling/strengthening effects of hydrogen, boron, and phosphorus on a {Sigma}5 nickel grain boundary

The embrittling/strengthening effects of hydrogen, boron, and phosphorus on a {Sigma}5(21O) [100]nickel grain boundary are investigated by means of the full-potential linearized augmented plane wave (FLAPW) method with the generalized gradient approximation (GGA) formula. Optimized geometries for both the free surface and grain boundary systems are obtained by atomic force calculations. The results obtained show that hydrogen and phosphorus are embrittlers and that boron acts as a cohesion enha… more

Date: July 1, 1999

Creator: Raynolds, J.E.; Geng, W.T.; Freeman, A.J.; Wu, R. & Geller, C.B.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

First principles total energy study of NbCr{sub 2} + V Laves phase ternary system

The C15 NbCr{sub 2} + V Laves phase ternary system is studied by using a first-principles, self-consistent, full-potential total energy method. Equilibrium lattice parameters, cohesive energies, density of states and formation energies of substitutional defects are calculated. Results of all these calculations show that in the C15 NbCr{sub 2} + V compounds, V atoms substitute Cr atoms only.

Date: April 1, 1999

Creator: Ormeci, A.; Chen, S. P.; Wills, J. M. & Albers, R. C.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

The effects of beryllium additions on the oxidation of nickel aluminide and titanium aluminide based intermetallics

The effects of Be additions on the oxidation behavior of {beta}-NiAl in moist air at 1,000 C and borderline alumina-forming {gamma} (TiAl) + Laves Ti-Al-Cr based alloys at 800 C and 1,000 C in dry and moist air were investigated. The addition of Be to {beta}-NiAl suppressed the formation of transient alumina, and resulted in the formation of a protective BeAl{sub 2}O{sub 4} spinel phase. In dry air, the addition of Be to the Ti-Al-Cr alloys also resulted in the formation of a protective BeAl{su… more

Date: December 31, 1998

Creator: Hanrahan, Robert J., Jr.; Chen, Katherine C. & Brady, Michael P.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Measurements of the diffusion of iron and carbon in single crystal NiAl using ion implantation and secondary ion mass spectrometry

Classical diffusion measurements in intermetallic compounds are often complicated by low diffusivities or low solubilities of the elements of interest. Using secondary ion mass spectrometry for measurements over a relatively shallow spatial range may be used to solve the problem of low diffusivity. In order to simultaneously obtain measurements on important impurity elements with low solubilities, the authors have used ion implantation to supersaturate a narrow layer near the surface. Single cr… more

Date: December 31, 1998

Creator: Hanrahan, R. J., Jr.; Withrow, S. P. & Puga-Lambers, M.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Boron strengthening in FeAl

The effect of boron on the strength of B2-structured FeAl is considered as a function of composition, grain size and temperature. Boron does not affect the concentrations of antisite atoms or vacancies present, with the former increasing and the latter decreasing with increasing deviation from the stoichiometric composition. When vacancies are absent, the strength increase per at. % B per unit lattice strain, {Delta}{sigma}/({Delta}c x {epsilon}) increases with increasing aluminum concentration… more

Date: November 1, 1998

Creator: Baker, I.; Li, X.; Xiao, H.; Klein, O.; Nelson, C.; Carleton, R. L. et al.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

The effects of beryllium additions on the oxidation of nickel aluminide and titanium aluminide based intermetallics

The effects of Be additions on the oxidation behavior of {beta}-NiAl in moist air at 1,000 C as well as on the borderline alumina-forming {gamma} + Laves Ti-Al-Cr based alloys at 800 C and 1,000 C in dry and moist air were investigated. The addition of Be to {beta}-NiAl suppressed the formation of transient alumina and resulted in the formation of a protective BeAl{sub 2}O{sub 4} spinel phase. In dry air, the addition of Be to the Ti-Al-Cr alloys also resulted in the formation of a protective B… more

Date: November 1, 1998

Creator: Hanrahan, Robert J., Jr.; Chen, Katherine C. & Brady, Michael P.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Solute hardening and softening effects in B2 nickel aluminides

The effect of substitutional solute additions including Fe, Mn, and Pd on the hardness of B2-ordered NiAl alloys was investigated. The solid solution hardening behavior of intermetallics is more complex than that of typical metallic solid solutions because of complications arising from the site preference of the solute as well as the effects of the solute on the concentrations of other point defects, e.g., vacancies and anti-site defects. For this reason, care was taken to experimentally establ… more

Date: November 1, 1998

Creator: Pike, L. M.; Liu, C. T.; Anderson, I. M. & Chang, Y. A.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Interactions of Zircaloy cladding with gallium: 1998 midyear status

A program has been implemented to evaluate the effect of gallium in mixed-oxide (MOX) fuel derived from weapons-grade (WG) plutonium on Zircaloy cladding performance. The objective is to demonstrate that low levels of gallium will not compromise the performance of the MOX fuel system in a light-water reactor. The graded, four-phase experimental program was designed to evaluate the performance of prototypic Zircaloy cladding materials against (1) liquid gallium (Phase 1), (2) various concentrati… more

Date: June 1, 1998

Creator: Wilson, D. F.; DiStefano, J. R.; Strizak, J. P.; King, J. F. & Manneschmidt, E. T.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

A study of Mo-V and Mo-V-Fe alloys for conductive cermet applications

Molybdenum and alumina cermets are currently being used for small, simple geometry, electrical feed-throughs in insulating alumina ceramic bodies. However, with larger and more complex geometries, high residual stresses and cracking of the alumina ceramic occur due to differences in coefficient of thermal expansion (CTE) between cermet and the surrounding 94% alumina. The difference in CTE is caused by the Mo in the cermet, which lowers the CTE of the cermet relative to the 94% alumina ceramic.… more

Date: June 1, 1998

Creator: Stephens, J. J.; Damkroger, B. K.; Ewsuk, K. G.; Glass, S. J.; Monroe, S. L.; Reece, M. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Gallium-cladding compatibility testing plan. Phases 1 and 2: Test plan for gallium corrosion tests; Revision 2

This test plan is a Level-2 document as defined in the Fissile Materials Disposition Program Light-Water-Reactor Mixed-Oxide Fuel Irradiation Test Project Plan. The plan summarizes and updates the projected Phases 1 and 2 Gallium-Cladding compatibility corrosion testing and the following post-test examination. This work will characterize the reactions and changes, if any, in mechanical properties that occur between Zircaloy clad and gallium or gallium oxide in the temperature range 30--700 C.

Date: May 1, 1998

Creator: Wilson, D.F. & Morris, R.N.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

The structure-property relationships of powder processed Fe-Al-Si alloys

Iron-aluminum alloys have been extensively evaluated as semi-continuous product such as sheet and bar, but have not been evaluated by net shape P/M processing techniques such as metal injection molding. The alloy compositions of iron-aluminum alloys have been optimized for room temperature ductility, but have limited high temperature strength. Hot extruded powder alloys in the Fe-Al-Si system have developed impressive mechanical properties, but the effects of sintering on mechanical properties … more

Date: February 23, 1998

Creator: Prichard, P.D.

Item Type: Thesis or Dissertation

Partner: UNT Libraries Government Documents Department