19 Matching Results

Search Results

Advanced search parameters have been applied.

HIGH TEMPERATURE OXIDATION RESISTANT COATINGS FOR TANTALUM BASE ALLOYS. Quarterly Progress Report No. 2, February 1, 1962 to April 30, 1962

Description: Tin-- aluminum base coatings applied by a cold spray-hot vacuum diffusion technique were studied further on Ta-10 W and Ta-10 Hf-5 W and work initiated on Ta--30 Nb--7t/2 V. Refractory additions to the coatings were optimized for Ta--10 W and the use of aluminum-silicon in tin was found beneficial for Ta--30 Nb--7 1/2 V. Furnace and oxy-acetylene torch tests were performed at temperatures from 1100 to over 3000 deg F. Diffusion treatments in vacuum, hydrogen, and argon were compared for coatings on Ta-10 W. Oxide formation on Ta--10 W coatings at various temperatures was studied by x-ray diffraction. The oxidation behavior of various tin--aluminum alloys and of the intermetallic (Ta--30 Nb--7 1/2 V) Al/sub 3/ was also studied, together with interactions of three alloys with A/sub 2/O/sub 3/ at elevated temperatures in vacuum. (auth)
Date: May 15, 1962
Creator: Sama, L.
Partner: UNT Libraries Government Documents Department

A PROGRAM OF BASIC RESEARCH ON MECHANICAL PROPERTIES OF REACTOR MATERIALS. Quarterly Progress Report for Period Ending March 31, 1962

Description: Studies were continued on the deformation and fabrication characteristics of reactor materials. Data were gathered on the effect of cold work on the internal friction due to dislocation relaxation oscillation. An interpretation was made of the internal-friction peak in niobium in terms of the relaxation motion of kinks on dislocations in niobium. Efforts were made to extend the technique of quantitative differential thermal analysis to cold-worked iron which was selected as the most readily treated representative of the body- centered-cubic structural metals. Refinements were made in the calorimetric technique itself, leading to an improved procedure of data reduction. Results for the effects of grain size on the stored-energyrelease spectra of high-purity copper were recomputed. (M.C.G.)
Date: May 1, 1962
Creator: Trozera, T.A.; Chambers, R.H. & White, J.L.
Partner: UNT Libraries Government Documents Department

Diffusion in Ceramic Systems. A Selected Bibliography

Description: References (165) on diffusion in ceramic systems such as oxides, silicates and glasses, borides, and carbides and graphite, are given to books, reports, and U.S. and foreign journals published from 1904 to 1961. Data on the frequency factor, Da, and activation energy, Q, are given for various elements and systems. A separate author index is also included. (P.C.H.)
Date: May 1, 1962
Creator: Berard, M. F.
Partner: UNT Libraries Government Documents Department

Calculation and Measurement of the Transient Temperature in a Low- Enrichment UO$sub 2$ Fuel Rod During Large Power Excursions

Description: The results of Spert I in-pile transient tests of a rodtype, low- enrichment UO/sub 2/ fuel element are presented. The tests were performed to investigate the possibility of damage to such long thermal-time-constant fuel rods when subjected to short-period power excursions, and to test the effectiveness of an instrumentation technique for measurement of UO/sub 2/ fuel temperatures within the rods. In an initial series of power excursion tests, in which the range of reactor periods was from approximately 1 sec to 7.5 msec, simultaneous measurements were made of the transient temperature at the center of the fuel rod and at the outer cladding surface. Fuel rod rupture occurred during the exponential rise of the 7.5-msec excursion. Similar short-period tests performed on a second fuel rod contain ing no internal thermocouples did not result in cladding failure, supporting the postulation that rupture of the first rod was caused by waterlogging of the UO/sub 2/ as a result of the cladding penetrations made for installation of the internal thermocouples. Calculations of the transient temperature distribution in the fuel rod were made, and the results are found to be in good agreement with the experimental data obtained on the central-UO/sub 2/ and cladding-surface transient temperatures. (auth)
Date: May 18, 1962
Creator: Houghtaling, J. E.; Quigley, T. M. & Spano, A. H.
Partner: UNT Libraries Government Documents Department

THE URANIUM-RICH END OF THE URANIUM-ZIRCONIUM SYSTEM. Final Report- Metallurgy Program 3.1.3.

Description: The uranium-rich end of the uranium-zirconium alloy system was reinvestigated. The solubilities of zirconium in alpha and beta uranium were found to be 0.21 wt% at 662 deg C and 0.41 wt% at 693 deg C, respectively. The monotectoid decomposition of gamma /sub 1/ at 693 deg C and the eutectoid decomposition of t 662 deg C were confirmed. For alloys containing less than 150 ppm of oxygen by weight, the gamma /sub 1/ plus gamma /sub 2/ phase region boundaries were located at 4.5 and 22.0 wt% zirconium at the monotectoid temperature. Data are given which indicate that oxygen concentrations ranging from 160 to 355 ppm by weight have a marked effect on phase relations in the area of the gamma /sub 1/ plus gamma /sub 2/ phase region. (auth)
Date: February 1, 1962
Creator: Zegler, S.T.
Partner: UNT Libraries Government Documents Department

BOILING WATER REACTOR TECHNOLOGY STATUS OF THE ART REPORT. VOLUME I. HEAT TRANSFER AND HYDRAULICS

Description: >Information on heat transfer and hydraulics pertinent to the design and operation of boiling water reactor power plants is presented. The following areas of discussion are covered: heat transfer, two-phase density studies, twophase pressure drop, critical heat flux and burnout, boiling stability, calculation procedures for boiling systems, and thermal-hydraulic design procedures for boiling water reactors. (M.C.G.)
Date: February 1, 1962
Creator: Lottes, P.A.
Partner: UNT Libraries Government Documents Department

PHASE TRANSFORMATIONS IN CALCINATION OF NITRATES OF ALUMINUM, STAINLESS STEEL, AND NICHROME

Description: Earlier studies showed that low concentrations of boric acid inhibit the formation of alpha alumina in the fluidized calcination of aluminum nitrate wastes. Studies designed to determine the optimum concentration of boric acid and the relative effectiveness of phosphoric acid were performed by heating synthetic mixtures at moderate pressure; results indicared that they were equally effective at the same molal concentration. Differential thermal analysis of mixtures showed that the boric acid reacted with alumina below 183 deg C. Extraction of boric acid from selected samples indicated that the B was bonded (probably in a random manner, as in glasses) to the alumina rather than to Na, Additlon of fission products was studied, and no unusual effects were found. Transformation studies on calcination of stainless steel nitrates indicate that alpha iron oxide is formed even with the addition of moderate amounts of addltives such as boric acid, phosphoric acid, aluminum nitrate, or combinations of these. Rare earths are the most effective additive found. Similar studies on nichrome wastes indicate that nickel oxide (crystalline) is formed even with additives. The studies include heating of synthetic mixtures at moderate pressure, differential thermal analysis, and use of a laboratory fluidized calciner. (auth)
Date: December 28, 1962
Creator: Eding, H J; Huggins, M L & Brown, A G
Partner: UNT Libraries Government Documents Department

CORROSION MECHANISM OF ZIRCONIUM AND ITS ALLOYS--DIFFUSION OF OXYGEN IN ZIRCONIUM DIOXIDE

Description: The diffusion rate of O in anion-deficient zirconia, ZrO/sub 1.994/, was determined by the interface migration of stoichiometric oxide and is represented by the equation D = 0.055 exp (--33,400 surface proces 3100/RT). A comparison was made with other processes that occur in the metal and the oxide. Excellent agreement was noted between activation energies of O diffusion in ZrO/sub 1.944/ and those for parabolic or cubic oxidation in both air and water. It appears that O diffusion in the oxide is rate-controlling during oxidation of the metal. The corrosion and oxidation behavior of Zr and some alloys are discussed in terms of the oxide defect structure and the electric conductivity behavior in the oxide. A speculative mechanism for corrosion transition to linear rates was suggested on the basis of preferential oxidation of a grain boundary metallic phase. The nature of the phase and of its formation and elimination are discussed. (auth)
Date: July 27, 1962
Creator: Douglass, D.L.
Partner: UNT Libraries Government Documents Department

IRRADIATION TESTING OF CERAMIC FUELS. Summary Report

Description: S>A research program was completed on the composition limits for single- phase face-centered cubic crystal structures in the ZrO/sub 2/-rich region of UO/ sub 2/-CaO-- ZrO/sub 2/ and in the CeO/sub 2/-rich end of UO/sub 2/-- CeO/sub 2/, on the fabrication of highdensity pellets from these cubic compositions of both systems, on the properties of these cubic compositions, and on the irradiation stability of these compositions. Phase studies are reported that confirm the occurrence of cubic regions in both UO/sub 2/-- ZrO/sub 2/-- CaO and UO/sub 2/-- CeO/sub 2/. The properties measured include thermal conductivity, thermal performance testing, melting points, and corrosion in water and steam. Progress in the irradiation program is described. (D. L. C.)
Date: September 1, 1962
Creator: Zuromsky, G & Chernock, W P
Partner: UNT Libraries Government Documents Department

SWELLING OF URANIUM AND URANIUM ALLOYS ON POSTIRRADIATION ANNEALING

Description: The swelling of U and of a few selected U alloys on postirradiation annealing was investigated by utilizing density measurements in conjunction with the observation of pores in the microstructures of annealed specimens. Speciniens were irradiated to about 0.3 at.% burnup in a constrained condition at approximately 275 deg C and were subsequently pulse annealed. The amount of swelling was found to be less than 1% for U specimens that were pulse annealed up to 75 hr at temperatures below 550 deg C; the amount of swelling, however, increased considerably on annealing at temperatures between 550 and 650 deg C. Specimens pulse annealed up to 75 hr at 618 deg C decreased in density by approximately 18%. The swelling was accompanied by the formation of bubbles on grain boundaries in recrystallized regions. The observations suggest that recrystallization is a necessary prerequisite for pronounced swelling in the alpha phase. Uranium specimens pulse annealed up to 75 hr at temperatures between 650 and 750 deg C in the BETA phase decreased in density by about 5%. Specimens annealed in the BETA phase, in contrast with those annealed at 618 deg C in the alpha phase, were badly cracked and contained pores of a smaller diameter, which were uniformly distributed within the grains. A specimen pulse annealed up to 16 hr at 822 deg C decreased in density, by, about 20%. This heat treatment produced pores of large diameter, located along grain boundaries, as well as pores of smaller diameter, distributed uniformly within the grains. Uranium alloys containing between 1 wt% and 9 wt% of either Ti, Zr, Nb, or Mo generally swelled more than pure U on pulse annealing up to 75 hr at 618 deg C and 740 deg C. An exception was the behavior of a U --4.0 wt % ...
Date: September 1, 1962
Creator: Loomis, B.A. & Pracht, D.W.
Partner: UNT Libraries Government Documents Department

INVESTIGATIONS IN THE SYSTEM URANIA - NEODYMIA

Description: Urania-neodymia compositions were sintered in air and in hydrogen. The compositions were studied by chemical, x ray, and differential thermal analyses. Solid solutions formed readily in air-sintered compositions in the range from 20 to 60 m/o Nd/sub 2/O/sub 3/. Solid solutions formed slowly and incompletely, up to 1650 deg C, in hydrogen-sintered compositions. There was good correlation between the differential thermal analyses and the chemical and x ray analyses. (auth)
Date: December 1, 1962
Creator: Kolar, D.; Handwerk, J.H. & Beals, R.J.
Partner: UNT Libraries Government Documents Department

INTERMEDIATE PHASES IN BINARY SYSTEMS OF TECHNETIUM-99 WITH SEVERAL TRANSITION ELEMENTS

Description: An exploratory survey was made of the intermediate phases formed when Tc/ sup 99/ is alloyed with the Sc, Ti, V, Cr, Mn, and Fe-group elements. A total of nineteen intermediate phases were identified and found to be isomorphous with the Cr/sub 3/O-type, CsCl-type, MgZn/sub 2/-type, gamma -phase, or sigma -phase structure. The alloying characteristics of Tc are rationalized in terms of periodic table relationships. (auth)
Date: December 1, 1962
Creator: Darby, Jr, J. B.; Lam, D. J.; Norton, L. J. & Downey, J. W.
Partner: UNT Libraries Government Documents Department

A Study of the Kinetic and Mechanical Properties of a Stabilized Beta Phase Plutonium Alloy

Description: The elements Sn, Mg, Ti, Zr, Hf, Si, Cd, and U were alloyed with plutonium to determine their effect on stabilization of the beta phase. Zirconium was found to be the ' most effective. Kinetic studies were conducted on Pu-Zr alloys having 0.24, 0.65, and 1.7 at.% Zr contents. The beta to alpha transformation in the Pu-Zr alloys was somewhat similar to that in unalloyed plutonium. The main difference being that time, temperature, transformation curves of the alloys were shifted to the right as the zirconium concentration increased. It was determined that the amount of beta phase retained at room temperature increased as the zirconium concentration increased. The minimum amount of Zr needed to stabilize the beta phase of plutonium at room temperature was determined to be 2.0 at.%. A 2.4 at.% Zr addition stabilized the beta phase of plutonium at atmospheric pressure from room temperature to 265 deg C. During mechanical property testing it was determined that the stabilized beta Pu-2.4 at.% Zr alloy was brittle from room temperature to 230 deg C. Both tensile and compression strengths of the beta stabilized alloy were greater than the unalloyed beta phase of plutonium. A brittle-ductile transition was noted between 130 and 180 deg C on the Pu-0.65 at.% Zr alloy. Age hardening studies were conducted at room temperature with a Pu -2.4 at.% Zr alloy. A slight aging effect was noted due to the precipitation of an intermetallic compound. Compression tests on the Pu-2.4 at.% Zr alloy indicated that below 80 deg C the stabilized beta phase started to transform to alpha phase during the application of compressive loads. (auth)
Date: January 1, 1962
Creator: Taylor, J. M.
Partner: UNT Libraries Government Documents Department

LABORATORY TECHNIQUES FOR VERY HIGH PRESSURES AND THE BEHAVIOR OF METALS UNDER DYNAMIC LOADING

Description: Particular attention is given to the production of very high pressures by colliding thin metal plates with stationary targets. Shock wave conservation equations are developed for this geometry that enable one to convert measurable quantities into equation of state data. Some results and techniques of high- pressure experiments are presented. Since the temperature rise behind a shock wave is not measurable, a brief description is given of how temperature estimates are made. Auxiliary experiments that support these calculations are also described. The hydrodynamic flow of the colliding plate experiment is outlined with attention given to the large dynamic tensions that can be produced. The effect of phase changes on the flow is also discussed, and it is shown how transition pressures can be determined by observing the freesurface motion of the target plate. The current work of several investigators on the elastic-plastic deformation of metal under dynamic conditions is reviewed and discussed with respect to calculational models and metallurgical studies made on shock-loaded specimens. (auth)
Date: January 1, 1962
Creator: McQueen, R G
Partner: UNT Libraries Government Documents Department

CERAMIC NUCLEAR FUELS IN THE SYSTEM ZrO$sub 2$-CaO-UO$sub 2$. Final Report

Description: Potential nuclear fuels in the system ZrO/sub 2/-CaO-UO/sub 2/ were investigated. Cubic fluorite-type solid solutions, as indicated by x-ray diffraction patterns, were formed by sintering CaO-stabilized ZrO/sub 2/ and U/ sub 3/O/sub 8/ compacts in either air or H/sub 2/. A continuous solid solution was found between urania and stabilized zirconia with H/sub 2/ sintering at 1750 deg C. Air sintering produced a limited region of solid solution in the stabilized zirconia portion of the system at 1450 deg C. Results on phase identification, oxidation behavior, and water corrosion are presented. (auth)
Date: September 1, 1962
Creator: Handwerk, J.H.; White, G.D. & Hill, D.C.
Partner: UNT Libraries Government Documents Department

FEASIBILITY STUDY ON THE DIFFUSION BONDING OF URANIUM

Description: Studies were made on the feasibility of effecting diffusion bonding in U, using pure Au as a catalyst, and by solid state diffusion without the use of a catalyst. It was found that the Au appeared to have promising characteristics for catalyzing the diffusion bonding reaction in joining uranium to itself. Phase diagrams are given U-Au, U--Cr, U--Co, U--Cu, U--Fe, U--Mn, and U--Ni alloys. (P.C.H.)
Date: October 15, 1962
Creator: Bertossa, R.C.
Partner: UNT Libraries Government Documents Department

THORIUM-MOLYBDENUM PHASE DIAGRAM

Description: The phase diagram of the Th-- Mo alloy system has been determined to be of the eutectic type with a eutectoid reaction associated with the Th alpha-beta transformation. X-ray, thermal, electric resistance, and metallographic methods have established the eutectic point at 1380 plus or minus 10 deg C and 7.0 plus or minus 0.5 wt% Mo. A eutectoid reaction is proposed at 1358 plus or minus 5 deg C and less than 0.1 wt% Mo. No solubility of Th in Mo was detected at 1325 deg C. (auth)
Date: March 27, 1962
Creator: McMasters, O.D.; Palmer, P.E. & Larsen, W.L.
Partner: UNT Libraries Government Documents Department