bluuebunny/crossref_metadata_2025_split huggingface dataset:
Wear Properties of A Shock Consolidated Metallic Glass and Glass-Crystalline Mixtures
Authors: Vreeland Thad , Thadhani Naresh N. , Mutz Andrew H. , Thomas Susan P. , Nibert Roger K. 
Published: March 2011

ABSTRACTPowder flakes prepared from 50 μm thick melt spun ribbons of Markomet 1064 (Ni52.5 Mo38 Cr8 B1.5 wt%) were shock consolidatedin the unannealed and annealed condition. The unannealed flakes (microhardness 933 kg/mm2) are amorphous while flakes annealed at 900ºC for 2 hours have an fcc structure with a grain size of 0.3 μm and microhardness of 800 kg/mm2. The shock consolidated amorphous powder compact (250 kJ/kg shock energy)shows no crystal peaks in an X-ray diffractometer scan. Compacts of annealed powder (400 to 600 kJ/kg shock energies) contain amorphous material (18-21%) which was rapidly quenched from the melt formed at interparticle regions during the consolidation process. The microhardness of the amorphous interparticle material is 1100 kg/mm2. Wear properties of the compacts measured in low velocity pin on disk tests show low average dynamic friction values (∿0.03). The 60 hour cumulative wear appears to correlate with the energy of shock compaction and surface porosity of the compacts rather than the metallic glass content.
Catalytic Properties of Glassy and Crystalline Transition Metal Alloys Produced by RSP
Authors: Mahmoud S.S. , Forsyth D.A. , Giessen B.C. 
Published: March 2011

ABSTRACTThe catalytic activity and selectivity of Pd80Si20, Pd35Zr65Ni30Zr70, Fe40Ni40B20, Fe85B15and Cu50Zr50alloy ribbons in their amorphous and crystalline states were studied in the hydrogenation of 1—hexene and phenylethyne, dehydrogenation of methylcyclohexane and dehydrocyclization of n—heptane. Pd80Si20was found to be the most active of the alloy catalysts studied. Most alloys were more active amorphous than in the crystalline state; however, the catalytic selectivities of the amorphous and crystalline states of each alloy were identical.
Magnetic after Effects and Magnetostriction of FE—Base Metallic Gzasses
Authors: Collins A.K. , O'Handley R.C. , Grant N.J. 
Published: March 2011

ABSTRACTMagnetic after effects (MAE's) have been studied in Fe—base and Co—base metallic glasses. Fe—base amorphous alloys shcw large MAE's due in part to the high magnetoelastic energy (large λs) whereas Co—basealloys exhibit much smaller MAE's due to their low magnetostriction. A detailed study of the acntribution of the magnetoelastic energy to the MAE's was done on the Fe83–xCrxB17 and Fe83–x NbxB17 glass systems.
Innovative Melt-Spinning Technique for Ferromagnetic Amorphous Ribbons
Authors: Yu H. Y. , Huang D. R. , Yao P. C. , Hsu S. E. 
Published: March 2011

ABSTRACTA new melt-spinning technique (field quenching) for ferromagnetic amorphous ribbon is suggested to produce better magnetic properties than conventional as-quenched amorphous ribbon. An external field is applied during the quenching either parallel or perpendicular to the casting direction. The magnetic moment and initial permeability are increased when the field direction is parallel to the casting direction. These effects are opposite when these two directions mentioned are perpendicular to each other.
Quasicrystals with 1-D Translational Periodicity and A Ten-Fold Rotation Axis
Authors: Bendersky L. 
Published: March 2011

ABSTRACTStudies of phase formation in rapidly solidified Al-Mn alloys (composition range 18-22 at% Mn) show that an icosahedral phase is replaced by another noncrystallographic phase, a decagonal phase. The decagonal phase is another example of quasicrystal: It has a noncrystallographic point group (10/m or lO/mmm) together with long-range orientational order and onedimensional translational symmetry. The decagonal phase is an intermediate phase between an icosahedral phase and a crystal both from the symmetry and from the solidification condition points of view.
Dispersoid Modification of Ti3Al-Nb Alloys
Authors: Rowe R. G. , Sutliff J. A. , Koch E. F. 
Published: March 2011

ABSTRACTTitanium aluminide alloys with matrix compositions of essentially Ti3Al plus 0, 5, 7.5, and 10 a/o Nb and with and without rare earth elements for dispersoid formation were prepared. The alloys were rapidly solidified by melt spinning. Ribbon was consolidated by HIP and extrusion at temperatures below the beta transus temperatures of the alloys. The effects of processing conditions and dispersoid additions on room temperature ductility and fracture toughness were studied.
Microstructure of Rapidly Solidified Ti3Al Alloys
Authors: Jackson A. G. , Teal K. R. , Eylon D. , Froes F. H. , Savage S. J. 
Published: March 2011

ABSTRACTThe microstructures of ordered Ti3Al-lZr (alpha2 +Zr) and Ti-Al-Nb alloys produced by ingot metallurgy (IM) and by rapid solidification (RS) are compared. The RS Ti3Al-iZr (alpha2 structure) alloy displayed small antiphase domains (APD) of 10–20 nm in the as-produced condition, but large grain size. The latter observation is rationalized in terms of the cooling history used to produce the material. The RS Ti-Al-Nb alloy exhibited an equiaxed microstructure. The IM Ti-Al-Nb material displays a complete change in microstructure between 1010°C and 1035°C, indicating a narrow alpha+beta phase field.
Shape Memory Behaviour in Rapidly Solidified TiNi Alloys
Authors: Igharo M. , Wood J.V. 
Published: March 2011

ABSTRACTEquiatomic TiNi alloy has been rapidly solidified by melt spinning. The M3 temperature of ribbon is depressed with respect to samples made from elemental powders. This phenomenon is related to grain refinement. Some of the ribbons have been crushed and the consolidation characteristics of the resulting pre-alloyed powder is compared with that of elemental blends. Sintering activity is higher in elemental compacts as a result of the dominant effect of the a]loy formation energy in elemental blends.
Comparison of Structures of Gas Atomized and of Emulsified Highly Undercooled Ni-Sn Alloy Droplets
Authors: Yamamoto Michiharu , Wu Yanzhong , Shiohara Yuh , Flemings Merton C. 
Published: March 2011

ABSTRACTA comparison is made of microstructures of droplets of Ni-Sn alloys rapidly solidified (a) by gas atomization and (b) in a glass emulsifying medium. Cooling rate of the gas atomized particles ranged from 103 to 106K/s depending on droplet diameter (20-230μm). In the hypoeutectic alloy studied (Ni-25wt%Sn), most particles showed a dendritic structure. These same particles, melted and resolidified in a glass medium using DTA (Differential Thermal Analysis), showed undercoolings up to 280K: the structures were dendritic at low undercoolings and non-dendritic at undercoolings above about 220K. It is concluded that (1) the gas atomized particles exhibited little or no undercooling before nucleation, (2) the solidification time of the undercooled emulsified droplets is substantially less than that of gas atomized droplets, and (3) the undercooling required to achieve non-dendritic structure depends on sample size.
Improvement of Thermal Fatigue Resistance of A Wrought Nickel-Base Superalloy by Laserglaze
Authors: Qi Zhao , Yunlong Ge , Zhuangqi Hu , Ming Jiang , Changshu Shih 
Published: March 2011

ABSTRACTLaserglaze with appropriate post heat treatment has improved the thermal fatigue resistance of a wrought nickel-base superalloy. It was found that laserglaze was able to eliminate the blocky MC phase, refine grains and form a very interesting microstructure of serrated grain boundaries. Careful selection of post heat treatment markedly increased the strength in the laser irradiated region. The initiation and propagation of thermal fatigue cracks were suppressed by this novel microstructure.
High Resolution Transmission Electron Microscope Study of Amorphous and Partially Crystalline Fe7 8B1 3Si9Alloy
Authors: Bhatti A.R. , Barry J.C. , Cantor B 
Published: March 2011

ABSTRACTAmorphous and partially crystalline Fe7 8B1 3Si9alloys have been examined by high resolution transmission electron microscopy at 200kV. In lattice imaging mode, the as-quenched alloy shows small regions, with a mean size of - 20Å, consisting of well defined patterns of fringes. Three different types of crystals can be identified at the very earliest stages of crystallisation of the alloy.
An Experimental Comparison of Alternative Solid Forms for Savannah River High-Level Wastes
Authors: Stone John A. 
Published: March 2011

ABSTRACTSamples of borosilicate glass, high-silica glass, tailored ceramic, and SYNROC, incorporating simulated Savannah River high-level defense waste sludges, were leached by the MCC-1 procedure for times up to 28 days. Cesium, uranium, and cerium leach rates are reported for waste forms containing a composite sludge, at 40°C in deionized water, and at 90°C in deionized water, silicate water, and brine. The ordering of the waste forms from best to worst differs for each element leached, and none of the forms show a clear advantage for all the key radwaste elements. Some cesium leach rates for forms containing high-aluminum or high-iron sludges also are presented. So far, only small effects of sludge type have been observed, with one exception. This study is one of several inputs for selection of an alternative waste form for Savannah River waste.
The System SrMoO4-BaMoO4-CaMoO4: Compatibility Relations, The Implications for Supercalcine Ceramics
Authors: Scheetz Barry E. , Phelps Freeborn W. , Pepin John , White William B. 
Published: March 2011

ABSTRACTThe stability of a tailored ceramic waste form under hydrothermal conditions was the subject of several previous papers [1,7–10] from this laboratory. One of the results reported in these studies was the apparent dissolution and reprecipitation of the alkaline-earth molybdate phases (scheelite-structure phase). The composition of the scheelite-structure phase after hydrothermal treatment was different from that before treatment (approximately Ca95 Sr5 after and Ca35 Sr40 Ba25 before). A schematic phase diagram was presented at that time to explain the results obtained.This paper is a report of our attempt to experimentally determine the phase relations in the alkaline-earth molybdate (Ca, Sr, and Ba) and verify our previous interpretation. For this work, we prepared compositions throughout the ternary system and heated them at 1200°C for periods of 2 to 24 hours. The experimental products were characterized by x-ray diffraction and SEM/EDX examination.At 1200°C, the two-phase solvus is nearly symmetric and extends from near the pure calcium and barium end-members to about 35 mole percent strontium at the critical point of the solvus. The increase in grain size, uniformity of composition within and between grains of the same phase and the approach to “textural equilibrium” in the 1200°C experiments all strongly suggest that equilibrium was attained.New, calcium-rich compositions are suggested for the scheelite-structure phases in the supercalcine-ceramics based upon the interpretation of data from this study. This observation forces a re-examination of the assumption concerning the partitioning of Sr and Ba amongst the phases in the supercalcine-ceramic.
Study of Polyhalite from the Wipp Site, New Mexico
Authors: Brookins Douglas G. 
Published: March 2011

ABSTRACTPolyhalite (K2Ca2Mg(SO4).2H2o) is an important mineral present in the bedded evaporites of the WIPP site, southeastern New Mexico. Polyhalite contains two structurally bonded water molecules, and it is thus important to know if this mineral formed at or close to the time of sedimentation or, as proposed by others (1,2) more or less continuously throughout the Mesozoic and Cenozoic. If formed much later than original evaporite formation, then this implies a new source of water in order for polyhalite to form in turn raising questions about water abundance and mobility in the bedded evaporites. Polyhalite is not well suited for Rb-Sr geochronologic study becauseof the large amounts of common Sr (3), but it has been shown to be suitable for study by the K-Ar geochronologic methods(4). Pure polyhalites and those mixed with very small amounts of impurities yield K-Ar dates in the range of 200 – 220 MYBP and indicate little if any, loss of *40Ar. Polyhalites mixed with sylvite, halite, and (Na,K)Cl yield lower ages due to loss of *40Ar from the halides. Apparent age lowering is proportional to halide content and an extrapolated age of formation of near 225 MYBP results. Collectively, the K-Ar data convincingly show that the polyhalites formed at the time of sedimentation (except for isolated occurrences near dike intrusions) in Late Permian time. Finally, thermodynamic calculations, supported by petrographic study, show that polyhalite is often stable with respect to carnallite, sylvite and other minerals formerly thought to be older than polyhalite.
Predictions of Radionuclide Migration Rates for a Subseabed Repository
Authors: Brush L. H. 
Published: March 2011

ABSTRACTGeochemical research carried out by the U.S. Subseabed Disposal Program is described. Data from studies of high temperature interactions between sediments and porewater (seawater), and of sorption and diffusion of radionuclides in oxidized, deep-sea sediments are used, along with results from heat transfer studies, to predict migration rates of radionuclides in a subseabed repository.Preliminary results for most radionuclides in oxidized sediments are very encouraging: fission products with moderate values of KD (generally 10 to 10 ml/g), and actinides with high values of KD (generally 103 to 106 ml/g) would not migrate significant distances before decaying to innocous concentrations. 137Cs, 90Sr, and 239Pu are among this group. The results for anionic species are less encouraging, but preliminary work with reduced sediments indicates that Tc can be effectively isolated.Planning for a field verification of these laboratory and modeling studies is also described.
Solidification of Radioactive Wastes With Thermosetting Resin
Authors: Hayashi M. , Kobayashi K. , Okamoto O. , Kagawa T. , Wakamatsu K. , Irie H. , Matsuura H. , Yasumura K. , Nakayama Y. 
Published: March 2011

ABSTRACTDried simulated radioactive wastes were solidified with thermosetting resin and their properties were investigated with laboratory scale and real scale products through extensive testings, such as mechanical resistance, resistance to leaching and swelling in water, radiation resistance, fire resistance and resistance to temperature cycling. The typical results were as follows: over 600 kg/cm2 of compressive strength, diffusion constant of ֮10−5 cm2/day for 137Cs leaching from solidified waste products, no significant change was found for up to 5 × 108 RAD irradiation, and damages were limited to the surface of the products after the thermal test and dropping impact test.
Processing of Titanates and Zeolites and use of a Cartridge System for ’Reactor‘ Wastes
Authors: Forberg S. , Westermark T. , Svärdströbm K. , FÄlth L. 
Published: March 2011

ABSTRACTNew methods were introduced in order to facilitate the production of i) very coarse-grain pure mordenite at a large scale ii) mono-disperse sodium titanate of a low price also at small volumes, and iii) a composite ion exchanger with up to 20 W-% of mordenite in beads of sodium titanate.Zeolites and titanates were converted to ceramic bodies by hot isostatic pressing at 1 300°C or by cold pressing followed by sintering at temperatures up to 1 300° C. Processed materials were zeolites, titanates and mixtures of them. The mechanical properties of sintered titanates were inferior to the hot pressed ones. Diffraction studies, static leaching at 40°C and Soxhlet leach tests were performed. The leach rates were much higher for mixed materials than for pure ones.For the handling of inorganic ion exchangers through all processes from packing of inactive beds and immobilization of radioactive species to the sintering or hot pressing for final disposal a system of cartridges is suggested. A lay-out of the system is presented together with some special arguments and some practical experiences. Simple, safe and hygienic operations with an optimal use of the inorganic sorbents are expected to result from this system.
Immobilization of Savannah River High-Level Wastes in Synroc: Results From Product Performance Tests
Authors: Campbell John H. , Hoenig Clarence L. , Bazan Fernando , Ryerson Frederick J. , Rozsa Rudolf 
Published: March 2011

ABSTRACTLarge samples (up to 15cm diameter) of SYNROC D containing simulated Savannah River (SRL) waste sludge have been prepared and performance tested. Waste loadings of 60-65 wt% for the SRL composite sludge have been achieved; this corresponds to a waste concentration (volumetric) loading of approximately 2.3-2.5 g/cm3. A typical SYNROC D sample has a density of about 4.0 g/cm3 with less than 0.2% porosity. The compressive and flexural strengths of SYNROC D are 51,200 and 9,400 psi, respectively and Young's Modulus is 20.1 × 106 psi by ultrasonic measurement. The quantity of respirable fines (less than 10 μm) generated during a constant energy density impact (10J/cm3) was less than 0.16 wt%. Values for the thermal conductivity (22°C) and the thermal expansion coefficient (22–950°C) were measured to be 1.7 W/m·K and 11 × 10−6 K−1, respectively. Normalized elemental leach rates determined by 28-day MCC-1 tests (90°C) for Cs, Sr, U and Nd are 0.7, 0.3, 5×10−5 and < 8×10−3 g/m2·d respectively.
Leaching Studies of Radionuclides from Solidified Wastes with Theremosetting Resin
Authors: Suzuki Kazunori , Kuribayashi Hiroshi , Morimitsu Wataru , Ono Isamu 
Published: March 2011

ABSTRACTThis paper reports on studies of the leachability of Co–60 and Cs–137 from simulated LWR radwastes solidified with thermosetting resin and evaluates the effects of chemical fixation on leachability. It is concluded that insolubilization by a nickel-ferrocyanide compound offers an effective chemical fixation of these radionuclides and is a recommended pretreating method for radwastes that are to be solidified.
Rheological Characterization of Cementitious Grouts used to Dispose of Intermediate-Level Radioactive Waste By Hydrofracturing at Oak Ridge National Laboratory
Authors: Mcdaniel E. W. , Moore J. G. 
Published: March 2011

ABSTRACTThe hydrofracturing process is a waste disposal process in use at the Oak Ridge National Laboratory for the permanent disposal of locally generated waste solutions. This process is now being modified for use in the disposal of sludge that results from the sodium hydroxide neutralization of acid waste solutions. In this process, the sludges will be slurried in a bentonite clay suspension and mixed with a solids blend of cement and other additives. The amount of dry solids required for each liter of waste slurry will be determined from a rheogram that relates the viscosity of the slurry with the grams per liter recommended for grouts with desirable flow properties.A description of the process and the development of rheograms are included. Data are presented on the use of chemical additives to control the flow properties of grouts.
Tailored ion Exchange Resins for Combined Cesium and Strontium Removal From Soluble Srp High-Level Waste
Authors: Ebra Martha A. , Wallace Richard M. , Walker Darrell D. , Wille Roice A. 
Published: March 2011

ABSTRACTNovel organic resins that achieve high selectivities for both cesium and strontium have been synthesized. They are condensation polymers of resorcinol and formaldehyde withattached chelating groups. Their column performance compares favorably with that of commercially available resins for either cesium or strontium removal. By combining Cs+ and Sr2+ removal in the same bed, these resins can significantly reduce the size and complexity of proposed facilities for processing defense high-level waste.
The Study of the Interaction of the Components of Imitator-Glasses of Glassified Radioactive Wastes With Various Surrounding Rocks
Authors: Spitsyn V. I. , Minaev A. A. , Barsova L. I. , Glazunov P. Ya. , Vetchkanov V. N. 
Published: March 2011

ABSTRACTThis work is one of the first attempts to work out a proper technique for the determination of the diffusion of the phosphate glass components into various rocks by using X-ray microanalysis. Under study was thermal and radiationenhanced diffusion of phosphorus, chromium from phosphate glasses into the samples of basalt, metagabbro, metadunite and quartz at high temperatures (to 600°) during gamma irradiation. Radiation enhanced diffusion of ions into rocks.
Development of Sphene-Based Glass Ceramics Tailored for Canadian Waste Disposal Conditions
Authors: Hayward Peter J. , Cecchetto E.V. 
Published: March 2011

ABSTRACTGlass ceramics and ceramics based on minerals of proven thermodynamic stability in Canadian Shield groundwaters are being developed to host the wastes arising from future CANDU* fuel recycling. Sphene-based glass ceramics, produced by melti0n g Na2 O-CaO-Al2O3-TiO2-SiO2 compositions at 1400° C, cooling, ang then reheating the phaseseparated glasses to approximately 1000° C, show strong partitioning of waste ions into the sphene (CaTiSiO5 ) lattice. Leaching results suggest that these materials are durable in deionized water. In simulated groundwaters, the sphene phase appears to suffer no net leaching. Leach testing and manufacturing methods are discussed.
Structural Inhomogeneities in Silicate Glass
Authors: Bochynski Zenon 
Published: March 2011

ABSTRACTLow- and wide-angle X-Ray scattering methods were applied to determine the size of structural inhomogeneities in the surface and internal layers of silicate glass.The functions of radial and cylindrical distribution of electron density in oxide glass, determined by Fourier-Bessel transformation method, were applied.The corrected structural parameters (mainly distances and packing coefficients) were obtained enabling preliminary determination of the most probable space model of glass. Structural inhomogeneities appearing due to defects and local distortions of the components of elementary space structure of glass, were determined.The method was applied in investigation of SiO2 in form of quartz glass and gel as well as the system SiO2-H2 O (hydrated gel). Them, it was transformed to investigation of a complex oxide glass (SiO2 -Na2 O-CaO-MgO-R2 O3).In result of the analysis we obtained the structural parameters of glass (a1, a2, a3, … , an; Zcl, Zc2, Zc3, …, Zcn) as well as the parameters describing degree of crystallization, concentration and size of inhomogeneities.
Effects of Radiation Induced Defects on Laser-Induced Breakdown in SiO2
Authors: Soileau M. J. , Mansour Nastaran , Canto Edesly , Griscom D. L. 
Published: March 2011

ABSTRACTThe effects of radiation damage on bulk laser-induced breakdown in Si02 were studied. Samples studied included Spectrasil A, B, and WF (water free). Measurements of laser-induced breakdown were conducted with 532 and 1064 nm laser pulses of approximately 30 nsec duration. Reductions of up to 50% in the laser-ind ced breakdown threshold were observed at 530 nm for samples exposed to 108 rads of γ-radiation.