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The Heat Treatment of Duralumin

Description: When certain light aluminum alloys are heat-treated, quenched and aged, there is considerable improvement in their tensile properties. This paper presents different methods of accomplishing these heat treatments.
Date: March 1927
Creator: Nelson, Wm.
Partner: UNT Libraries Government Documents Department

Performance of as-forged, heat-treated, and overaged S-816 blades in a turbojet engine

Description: Report presenting an investigation to study the effects of several heat treatments on the operating life of turbine blades in a J33-33 turbojet engine operated without an afterburner. As-forged blades, blades solution treated at temperatures high enough to produce germinated grains, blades given a double-aging treatment, and blades overaged by overtemperature heat treatments are evaluated. Results regarding the engine operating results and blade performance, metallurgical studies of as-heat-treated specimens, and metallurgical studies of failed blades are provided.
Date: March 3, 1955
Creator: Weeton, J. W.; Clauss, F. J. & Johnston, J. R.
Partner: UNT Libraries Government Documents Department

Effect of heat treatment upon the microstructure and hardness of a wrought cobalt-base alloy stellite 21 (AMS 5385)

Description: Report presenting an investigation of the response of wrought Stellite 21, a typical cobalt-base alloy, to heat treatment. The alloy was solution-treated and transformed by aging and isothermal transformation at temperatures of 1200 to 1950 degrees Fahrenheit for periods of 5 minutes to 72 hours. Results regarding the solution-treated structure, precipitation by isothermal transformation, precipitation by aging, grain boundary behavior, and hardness are provided.
Date: March 1954
Creator: Clauss, F. J. & Weeton, J. W.
Partner: UNT Libraries Government Documents Department

Loss of Radioactivity from Barium Carbonate Samples

Description: The exchange loss of radioactivity from solid samplos of barium carbonate through the agency of carbonic acid and its ions has been investigated under a variety of conditions. It is concluded that the losses observed are greatly dependent upon the method of sample preparation, in particular the nature or any heat treatment which the sample materials undergo.
Date: January 9, 1948
Creator: Yankwich, Peter E.
Partner: UNT Libraries Government Documents Department

A SUMMARY OF THE WORK ASSOCIATED WITH THE SOLUTION AND UNDERSTANDING OF STRINGER-TYPE CORROSION IN ZIRCALOY-2 AND -3

Description: This report summarizes the work performed to eliminate stringer-type corrosion from Zircaloy-2 and Zircaloy-3. The investigation included a study of the melting and fabrication variables of the alloys. Metallographic and thermal treatment studies identified the problem to be inert atmosphere melting. Based on this work, a stringer formation mechanism has been postulated. (auth)
Date: April 1, 1959
Creator: Goodwin, J.G.; Rubenstein, L.S.; Grozier, J.D. & Shubert, F.L.
Partner: UNT Libraries Government Documents Department

Stress corrosion cracking behavior of Alloy 600 in high temperature water

Description: SCC susceptibility of Alloy 600 in deaerated water at 360 C (statically loaded U-bend specimens) is dependent on microstructure and whether the material was cold-worked and annealed (CWA) or hot-worked and annealed (HWA). All cracking was intergranular, and materials lacking grain boundary carbides were most susceptible to SCC initiation. CWA tubing materials are more susceptible to SCC initiation than HWA ring-rolled forging materials with similar microstructures (optical metallography). In CWA tubing materials, one crack dominated and grew to a visible size. HWA materials with a low hot-working finishing temperature (<925 C) and final anneals at 1010-1065 C developed both large cracks (similar to those in CWA materials) and small intergranular microcracks detectable only by destructive metallography. HWA materials with a high hot-working finishing temperature (>980 C) and a high-temperature final anneal (>1040 C), with grain boundaries that are fully decorated, developed only microcracks in all specimens. These materials did not develop large, visually detectable cracks, even after more than 300 weeks exposure. A low-temperature thermal treatment (610 C for 7h), which reduces or eliminates SCC in Alloy 600, did not eliminate microcrack formation in high temperature processed HWA materials. Conventional metallographic and analytical electron microscopy (AEM) were done on selected materials to identify the factors responsible for the observed differences in cracking behavior. Major difference between high-temperature HWA and low-temperature HWA and CWA materials was that the high temperature processing and final annealing produced predominantly ``semi-continuous`` dendritic M{sub 7}C{sub 3} carbides along grain boundaries with a minimal amount of intragranular carbides. Lower temperature processing produced intragranular M7C3 carbides, with less intergranular carbides.
Date: July 1, 1995
Creator: Webb, G.L. & Burke, M.G.
Partner: UNT Libraries Government Documents Department

OPTIMIZING CENTRIFUGAL BARREL POLISHING FOR MIRROR FINISH SRF CAVITY AND RF TESTS AT JEFFERSON LAB

Description: We performed Centrifugal Barrel Polishing (CBP) on a 1.3 GHz fine grain TESLA single cell cavity and 1.5 GHz fine grain CEBAF high gradient superconducting radio frequency (SRF) single cell cavity following a modified recipe originally developed at Fermi National Accelerator Lab (FNAL). We were able to obtain a mirror like surface similar to that obtained at FNAL, while reducing the number of CBP steps and total processing time. This paper will discuss the change in surface and subsequent cavity performance post CBP, after a 800 C bake (no pre-bake chemistry) and minimal controlled electro-polishing (10 micron). In addition to Q vs. E{sub ACC} thermometry mapping with preheating characteristics and optical inspection of the cavity after CBP will also be shown.
Date: July 1, 2012
Creator: Ari Palczewski, Rongli Geng, Hui Tian
Partner: UNT Libraries Government Documents Department

PREPARATION AND CHARACTERIZATION OF POROUS WALLED HOLLOW GLASS MICROSPHERES

Description: Porous-walled hollow glass microspheres (PWHGMs) of a modified alkali borosilicate composition have been successfully fabricated by combining the technology of producing hollow glass microspheres (HGMs) with the knowledge associated with porous glasses. HGMs are first formed by a powder glass--flame process, which are then transformed to PWHGMs by heat treatment and subsequent treatment in acid. Pore diameter and pore volume are most influenced by heat treatment temperature. Pore diameter is increased by a factor of 10 when samples are heat treated prior to acid leaching; 100 {angstrom} in non-heat treated samples to 1000 {angstrom} in samples heat treated at 600 C for 8 hours. As heat treatment time is increased from 8 hours to 24 hours there is a slight shift increase in pore diameter and little or no change in pore volume.
Date: April 21, 2008
Creator: Raszewski, F; Erich Hansen, E; Ray Schumacher, R & David Peeler, D
Partner: UNT Libraries Government Documents Department

Development of Wind-and-React Bi-2212 Accelerator Magnet Technology

Description: We report on the progress in our R&amp;D program, targeted to develop the technology for the application of Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub x} (Bi-2212) in accelerator magnets. The program uses subscale coils, wound from insulated cables, to study suitable materials, heat treatment homogeneity, stability, and effects of magnetic field and thermal and electro-magnetic loads. We have addressed material and reaction related issues and report on the fabrication, heat treatment, and analysis of subscale Bi-2212 coils. Such coils can carry a current on the order of 5000 A and generate, in various support structures, magnetic fields from 2.6 to 9.9 T. Successful coils are therefore targeted towards a hybrid Nb{sub 3}Sn-HTS magnet which will demonstrate the feasibility of Bi-2212 for accelerator magnets, and open a new magnetic field realm, beyond what is achievable with Nb{sub 3}Sn.
Date: June 1, 2007
Creator: Cheng, Daniel; Dietderich, Daniel R.; English, C.D.; Felice, Helene; Hannaford, Charles R.; Prestemon, Soren O. et al.
Partner: UNT Libraries Government Documents Department

Influence of carbon partitioning kinetics on final Austenite fraction during quenching and partitioning

Description: The quenching and partitioning (Q&amp;P) process is a two-stage heat-treatment procedure proposed for producing steel microstructures that contain carbon-enriched retained austenite. In Q&amp;P processing, austenite stabilization is accomplished by carbon partitioning from supersaturated martensite. A quench temperature selection methodology was developed to predict an optimum process quench temperature; extension of this methodology to include carbon partitioning kinetics is developed here. Final austenite fraction is less sensitive to quench temperature than previously predicted, in agreement with experimental results.
Date: January 1, 2009
Creator: Clarke, Amy J; Speer, John G; Matlock, David K; Rizzo, F C; Edmonds, David V & Santofimia, Maria J
Partner: UNT Libraries Government Documents Department

The early stages of microstructural development of the colony structure in Bi-2223 tapes.

Description: The current protocol for processing (Bi,Pb)2Sr2Ca2Cu3010-(B i-2223) multifilamentary tapes involves the in situ formation of the primary phase from a suitable mixture of precursor phases. As such, the developments during the first few minutes of heat treatment determine to a large extent the efficiency of primary phase development, competing secondary phase development, texture evolution, and grain-to-grain connectivity. This work documents the development of the liquid phase, secondary phases, defects which may affect alignment and reaction kinetics, and the precipitation of Bi-2223 from the liquid phase.
Date: January 1, 2001
Creator: Holesinger, T. G. (Terry G.)
Partner: UNT Libraries Government Documents Department

RRP Nb3Sn Strand Studies for LARP

Description: The Nb{sub 3}Sn strand chosen for the next step in the magnet R&amp;D of the U.S. LHC Accelerator Research Program is the 54/61 sub-element Restacked Rod Process by Oxford Instruments, Superconducting Technology. To ensure that the 0.7 mm RRP strands to be used in the upcoming LARP magnets are suitable, extensive studies were performed. Measurements included the critical current, I{sub c}, using the voltage-current (V-I) method, the stability current, I{sub S}, as the minimal quench current obtained with the voltage-field (V-H) method, and RRR. Magnetization was measured at low and high fields to determine the effective filament size and to detect flux jumps. Effects of heat treatment temperature and durations on I{sub c} and I{sub S} were also studied. Using strand billet qualification and tests of strands extracted from cables, the short sample limits of magnet performance were obtained. The details and the results of this investigation are herein described.
Date: June 1, 2007
Creator: Barzi, Emanuela; Bossert, Rodger; Caspi, Shlomo; Dietderich, Daniel R.; Ferracin, Paolo; Ghosh, Arup et al.
Partner: UNT Libraries Government Documents Department

Tungsten Cladding of Tungsten-Uranium Dioxide (W-UO2) Composites by Deposition from Tungsten Hexafluoride (WF6)

Description: A program is being conducted to develop a process for cladding tungsten and tungsten cermet fuels with tungsten deposited from the vapor state by the hydrogen reduction of tungsten hexafluoride. Early work was performed using recrystallized, high purity, commercial tungsten as the substrate material. Temperatures in the range 660 to 12950F (350 to 1700°C) and pressures from 10 to 350 mm Hg were investigated. Hydrogen to WF 6 ratios of 10: 1 to 150: 1 were utilized. Efforts were directed toward optimizing deposition process parameters to attain control of qualities such as coating thickness, uniformity, density, impurity content, and surface quality. Substrate penetration methods have been investigated in the interest of completely eliminating the interface between the fueled substrate and cladding. In addition, the effects of process parameters and post-cladding heat treatments on the fuel retention properties of clad composites at 4500 degrees F (2480 degrees C) in hydrogen for 2 hours have been evaluated. As a result of work performed during the first phase of the program it has been shown that the rate of deposition of tungsten from WF 6 and the uniformity of the deposit can be varied in a predictable and reproducible manner by exercising control over the temperature, pressure, and gas flow rates at which the deposits are produced. A significant result of the study is the discovery that substrate nucleation and epitaxial growth in deposits made on both unfueled tungsten and fueled substrates may be effected by pretreating the substrates in hydrogen. High temperature fuel retention testing of tungsten clad W-U02 at 45000F (2480 degrees C) in hydrogen for 2 hours has demonstrated that the vapor deposited layer effectively and consistently restricts fuel loss.
Date: February 15, 1965
Creator: Lamartine, J.T. & Hoppe, A.W.
Partner: UNT Libraries Government Documents Department

Sintering and robocasting of beta-tricalcium phosphate scaffoldsfor orthopaedic applications

Description: {beta}-tricalcium phosphate ({beta}-TCP) scaffolds with designed, three-dimensional (3-D) geometry and mesoscale porosity have been fabricated by direct-write assembly (robocasting) techniques. Concentrated {beta}-TCP inks with suitable viscoelastic properties were developed to enable the fabrication of the complex 3-D structures. A comprehensive study of the sintering behavior of TCP as a function of the calcium content in the starting powder was also carried out, and the optimal heat treatment for fabricating scaffolds with dense {beta}-TCP rods has been determined. Such analysis provides clues to controlling the microstructure of the fabricated structures and, therefore, enabling the fabrication by robocasting of TCP scaffolds with tailored performance for bone tissue engineering applications.
Date: November 1, 2005
Creator: Miranda, Pedro; Saiz, Eduardo; Karol, Gryn & Tomsia, Antoni P.
Partner: UNT Libraries Government Documents Department

Improvement and protection of niobium surface superconductivity by atomic layer deposition and heat treatment

Description: A method to treat the surface of Nb is described, which potentially can improve the performance of superconducting rf cavities. We present tunneling and x-ray photoemission spectroscopy measurements at the surface of cavity-grade niobium samples coated with a 3 nm alumina overlayer deposited by atomic layer deposition. The coated samples baked in ultrahigh vacuum at low temperature degraded superconducting surface. However, at temperatures above 450 C, the tunneling conductance curves show significant improvements in the superconducting density of states compared with untreated surfaces.
Date: November 1, 2008
Creator: Proslier, T.; Zasadzinski, J.; Moore, J.; Pellin, M.; Elam, J.; Cooley, L. et al.
Partner: UNT Libraries Government Documents Department

METALLOGRAPHY OF PYROLYTIC CARBON COATED AND UNCOATED URANIUM CARBIDE SPHERES

Description: Metallographic techniques are described which were developed for examining coated and uncoated uranium carbid particles, both in the unsupported condition and in graphite matrices. The structural and compositional variations in various batches and within a given batch are presented, and the effects of various heat treatments on the particles and the coatings are described. (D.L.C.)
Date: March 21, 1962
Creator: DuBose, C.K.H. & Gray, R.J.
Partner: UNT Libraries Government Documents Department

Thermally Induced Reorganization in LCP Fibers: Molecular Origin of Mechanical Strength

Description: The ordering of liquid crystalline polymer fiber during heat treatment is of great interest for many commercial reasons. This is because, by convention, fiber property can be greatly improved by heat-treatment at below the melting temperature and often such processing conditions are also very complex. There are many variations of such treatments, in terms of temperature, exposure time and whether the fibers are under tension or not. The state-of-the-art technology will be to optimize the desired property without significantly enhancing the undesired properties. The types of heat treatment are highly correlated to the understanding of the mechanism of improving the properties at the molecular level and the microstructures. Using WAXS and synchrotron SAXS techniques, the structure and morphology of our commercial LCP (liquid crystalline polymer), a co-polymer of CO (Vectran) and its variant polymer fiber COTHBP are being examined. Both fibers have the typical liquid crystalline polymer structure, ie, highly ordered across the fiber axis and aperiodic sequencing along the fiber axis. Physical testing has revealed a three fold increase in strength in both fibers, however, the modulus is observed to increase significantly in COTBP and not so much CO. This paper reports on the changes and the differences on the structural and morphological behavior for both the as-spun and heat-treated LCP fibers. We have also use thermal analysis technique to provide a guide to the heat-treatment cycle. We propose an 'organized kinks' model to describe the differences between the two polymer fibers. Future publication will focus on the in-situ behavior at elevated temperatures and under heat-treatment.
Date: July 16, 2007
Creator: Saw, C K; Collins, G; Menczel, J & Jaffe, M
Partner: UNT Libraries Government Documents Department

PRELIMINARY EXPERIMENTS ON IRRADIATION CYCLING AND PARTIAL BETA-PHASE IRRADIATION OF URANIUM

Description: A group of uranium specimens were irradiated under conditions in which some of the specimens were irradiated continuously while others were cycled in and out of a reactor. Although most of the specimens were irradiated under conditions in which they were entirely in the alpha phase, some were irradiated so that their centers were above alpha-phase temperatures. Both highly textured material (300 deg C rolled) and nomimally randomly oriented material (300 deg C rolled and beta-quenched) were studied. It appeared that irradiation cycling of both types of material may result in greater elongation than would be anticipated on the assumption that the effects of irradiation and thermal cycling acting alone were additive. The material rolled at 300 deg C showed no external effects due to central irradiation temperatures being above those limiting the alpha phase. However, betaquenched material, which was irradiated so that central temperatures were above those required for stability of the alpha phase, developed severe distortions which were greater under cycling conditions. It was also noted that 300 deg C rolled uranium begins to elongate under irradiation at burnups as low as 0.0002 a/o (2 Mwd/t). (auth)
Date: April 1, 1959
Creator: Kittel, J.H.
Partner: UNT Libraries Government Documents Department