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Microstructural evolution in elastically stressed systems. Final report

Description: The results, which have been compared to numerical simulations and found to be in very good agreement, predict that diviations in composition on the order of several atomic percent (measured with respect to equilibrium compositions) are possible at the interface. Interfacial compositions are strongly time dependent and are also influenced by the stress state.
Date: September 14, 1997
Creator: Johnson, W.C.
Item Type: Report
Partner: UNT Libraries Government Documents Department

Method of making steel strapping and strip

Description: The technical progress obtained for this time frame consisted of the awarding of two contracts for determination of metallurgical parameters for heat treatment of strapping and strip which are unavailable from current technology and/or published data in this field. The two contractors were Bricmont, Inc. and the Department of Materials Science and Engineering at the Technological Institute of Northwestern University, Evanston, IL. Phase 1 of the two stage contract with Bricmont, Inc. which provided a computer analysis of the cooling rates of a typical range of thickness' of strapping was completed. This study was developed for the purpose of determining the time parameters for quenching low carbon steels to a martensitic microstructure within the time frame of the design of the proposed process. It also provides design criteria for cooling to ambient for the total process. This data is required for Phase 2 of the Bricmont proposal which completes the design and specifications of the total heat treating and cooling system for the process. This becomes the basis for developing the cost and space requirements for this component of the production line. The authors do not intend to award Phase 2 until the work done at Northwestern University discussed hereafter is completed. On or about May 1, 1999 a contract for a project entitled ``Effects of Steel Composition and Quench Rate on Microstructure and Mechanical Properties of Strapping'' to be performed at the Department of Materials Science and Engineering was awarded. The delay in initiating this project was due to the legal interpretation and final agreement of the intellectual provisions of the award by the author's attorneys, Northwestern's attorneys and the legal representative in the Chicago office of the DOE. The work to date includes rapid quenching of a number of different steel compositions and microstructure on an existing drop ...
Date: February 16, 2000
Creator: Reilly, Robert D.
Item Type: Report
Partner: UNT Libraries Government Documents Department

A New Process for Hot Metal Production at Low Fuel Rate - Phase 1 Feasibility Study

Description: The project is part of the continuing effort by the North American steel industry to develop a coal-based, cokeless process for hot metal production. The objective of Phase 1 is to determine the feasibility of designing and constructing a pilot scale facility with the capacity of 42,000 mtpy of direct reduced iron (DRI) with 95% metallization. The primary effort is performed by Bricmont, Inc., an international engineering firm, under the supervision of McMaster University. The study focused on the Paired Straight Hearth furnace concept developed previously by McMaster University, The American Iron and Steel Institute and the US Department of Energy.
Date: February 1, 2006
Creator: Lu, Dr. Wei-Kao
Item Type: Report
Partner: UNT Libraries Government Documents Department

Multiplexed Optical Fiber Sensors for Coal Fired Advanced Fossil Energy Systems

Description: This report summarizes technical progress on the program “Multiplexed Optical Fiber Sensors for Coal Fired Advanced Fossil Energy Systems” funded by the National Energy Technology Laboratory of the U.S. Department of Energy, and performed jointly by the Center for Photonics Technology of the Bradley Department of Electrical and Computer Engineering and the Department of Materials Science and Engineering at Virginia Tech. This three-year project started on October 1, 2008. In the project, a fiber optical sensing system based on intrinsic Fabry-Perot Interferometer (IFPI) was developed for strain and temperature measurements for Ultra Supercritical boiler condition assessment. Investigations were focused on sensor design, fabrication, attachment techniques and novel materials for high temperature and strain measurements. At the start of the project, the technical requirements for the sensing technology were determined together with our industrial partner Alstom Power. As is demonstrated in Chapter 4, all the technical requirements are successfully met. The success of the technology extended beyond laboratory test; its capability was further validated through the field test at DOE NETL, in which the sensors yielded distributed temperature mapping of a testing coupon installed in the turbine test rig. The measurement results agreed well with prior results generated with thermocouples. In this project, significant improvements were made to the IFPI sensor technology by splicing condition optimization, transmission loss reduction, sensor signal demodulation and sensor system design.
Date: December 31, 2011
Creator: Wang, Anbo & Pickrell, Gary
Item Type: Report
Partner: UNT Libraries Government Documents Department

Laser welding of automotive aluminum alloys to achieve defect-free, structurally sound and reliable welds

Description: The objective of this program was to seek improved process control and weldment reliability during laser welding of automotive aluminum alloys while retaining the high speed and accuracy of the laser beam welding process. The effects of various welding variables on the loss of alloying elements and the formation of porosity and other geometric weld defects such as underfill and overfill were studied both experimentally and theoretically.
Date: November 17, 2000
Creator: DebRoy, T.
Item Type: Report
Partner: UNT Libraries Government Documents Department

Final report for grant: DE-FG02-93ER45481 [Polymers at engineered interfaces]

Description: Studies have been made of polymer interfaces, self-assembly of micelles at surfaces, phase separation in blends, diffusion and dewetting at and near interfaces, and nanomechanical properties of thin films. The main projects are summarized under the following topics: dislocations in lamellar diblock structures, effects of surface tension; compliance measurements and profiles of end-grafted polystyrene in solution observed by atomic force microscopy and neutron reflectivity; self-assembly of diblock polymer micelles from solution; dewetting dynamics; polymers on patterned surfaces; Flory-Huggins interaction parameter for polystyrene/poly-2-vinylpyridine (PS/P{sub 4}VP) blends; phase separation-induced patterns in dPS/PVME and dPEP/PEP blends; and high-resolution lateral imaging studies of phase separation and dewetting by scanning transmission X-ray microscopy (STXM) and photoemission electron microscopy (PEEM).
Date: January 17, 2000
Creator: Rafailovich, Miriam & Sokolov, Jonathan
Item Type: Report
Partner: UNT Libraries Government Documents Department

High temperature alkali corrosion of dense SiC and Si{sub 3}N{sub 4} coated with CMZP and Mg-Doped Al{sub 2}TiO{sub 5} in Coal Gas: Quarterly progress No. 9, July 1, 1996-September 30, 1996

Description: The second phase, coating of Si{sub 3}N{sub 4} by oxides, was started during this reporting period. Si{sub 3}N{sub 4} samples were coated by CMZP and Mg-coated Al{sub 2}TiO{sub 5} by a double-dip procedure.
Date: October 15, 1996
Creator: Brown, J.J.
Item Type: Report
Partner: UNT Libraries Government Documents Department

Environmental scanning electron microscope (ESEM). Final report

Description: The Environmental Scanning Electron Microscope (ESEM) was acquired by a grant from the Department of Energy University Research Instrumentation Program and matching funds from Lehigh University and industry. The equipment is installed as part of the electron microscopy laboratories and is being utilized on a regular basis. Over 20 graduate and undergraduate students from the Department of Materials Science and Engineering as well as other department in the University have included this instrument in their research. In addition, the ESEM has been used in several courses including MAT 427 -- Advanced Scanning Electron Microscopy, a graduate course offered every other year. Examples are given of how the ESEM has been included in the research programs.
Date: November 1, 1998
Creator: Marder, A.; Barmak, K. & Williams, D.
Item Type: Report
Partner: UNT Libraries Government Documents Department

Development of instrumentation for surface, interface and thin film science at the Advanced Photon Source. Final Technical Report for period September 15, 1994 - September 14, 2000

Description: The P.I. and his research term successfully used the funds from the DOE Instrumentation grant entitled ''Development of Instrumentation for Surface, Interface and Thin Film Science at the Advanced Photon Source'' to design, build, test, and commission a customized surface science x-ray scattering/spectroscopy chamber. This instrumentation, which is presently in use at an APS x-ray undulator beam line operated by the DuPont-Northwestern-Dow Collaborative Access Team, is used for x-ray measurements of surface, interface, thin film, and nano-structures.
Date: September 2000
Creator: Bedzyk, Michael J.
Item Type: Report
Partner: UNT Libraries Government Documents Department

Final technical report to Department of Energy, Basic Energy Sciences. ''Oxide ceramic alloys and microlaminates'' (1996-1999) and ''Low temperature processing and kinetics of ceramics and ceramic matrix composites with large interfacial areas'' (1999-2000)

Description: We have discovered a novel two-step sintering method that opened up a low temperature processing window within which fully dense nanocrystalline yttrium oxide was obtained with no concurrent grain growth during final-stage sintering. We have developed a new method of processing laminate ceramics using deformation processing in the green state. We have lastly developed a colloidal processing technique to encapsulate biomolecules at ambient, neutral-pH, aqueous conditions.
Date: March 26, 2001
Creator: Chen, I-Wei
Item Type: Report
Partner: UNT Libraries Government Documents Department

Atomistic studies of grain boundaries and heterophase interfaces in alloys and compounds. Final report, July 1987-August 1998

Description: The overarching goal of the research supported by this grant was investigation of the structure and properties of interfaces in multicomponent systems by atomistic modeling. Initially, the research was devoted to studies of segregation to grain boundaries in binary disordered alloys. The next step was then studies of the structure and properties of grain boundaries in ordered compounds, specifically Ni3Al and NiAl, and grain boundary segregation in these compounds in the case of off-stoichiometry. Finally, the structure of Nb/sapphire interfaces, in particular the core configurations of the misfit dislocations, was studied.
Date: August 1, 1998
Creator: Vitek, Vaclav
Item Type: Report
Partner: UNT Libraries Government Documents Department

Reliability and Consistency of Surface Contamination Measurements

Description: Surface contamination evaluation is a tough problem since it is difficult to isolate the radiations emitted by the surface, especially in a highly irradiating atmosphere. In that case the only possibility is to evaluate smearable (removeable) contamination since ex-situ countings are possible. Unfortunately, according to our experience at CEA, these values are not consistent and thus non relevant. In this study, we show, using in-situ Fourier Transform Infra Red spectrometry on contaminated metal samples, that fixed contamination seems to be chemisorbed and removeable contamination seems to be physisorbed. The distribution between fixed and removeable contamination appears to be variable. Chemical equilibria and reversible ion exchange mechanisms are involved and are closely linked to environmental conditions such as humidity and temperature. Measurements of smearable contamination only give an indication of the state of these equilibria between fixed and removeable contamination at the time and in the environmental conditions the measurements were made.
Date: February 26, 2002
Creator: Rouppert, F.; Rivoallan, A. & Largeron, C.
Item Type: Article
Partner: UNT Libraries Government Documents Department

Reduction of Annealing Times for Energy Conservation in Aluminum

Description: Carnegie Mellon University was teamed with the Alcoa Technical Center with support from the US Dept. of Energy (Office of Industrial Technology) and the Pennsylvania Technology Investment Authority (PTIA) to make processing of aluminum less costly and more energy efficient. Researchers in the Department of Materials Science and Engineering have investigated how annealing processes in the early stages of aluminum processing affect the structure and properties of the material. Annealing at high temperatures consumes significant amounts of time and energy. By making detailed measurements of the crystallography and morphology of internal structural changes they have generated new information that will provide a scientific basis for shortening processing times and consuming less energy during annealing.
Date: August 31, 2005
Creator: Rollett, Anthony D.; Weiland, Hasso; Alvi, Mohammed & Brahme, Abhijit
Item Type: Report
Partner: UNT Libraries Government Documents Department

Final report for Grant DE-FG02-97ER45655

Description: Studies were performed of the Au/SiC interface, as well as the interfaces between SiC and several Au alloys. A contact angle of 133{+-}1{sup o} for pure Au on SiC was obtained after equilibration at 800 C. Au containing 3at%Sn was studied, and wetting was improved as evidenced by a decrease in contact angle from 133{sup o} for pure Au to 117{sup o} for the Au-Sn alloy. Sn segregation was observed at the surface of Au. Measurements were also performed on Au-Ge alloys. It was found that the contact angle is decreased to 115{sup o} and 107{sup o} at Ge concentrations of 1 and 2 at%, respectively. Studies of Au containing a low concentration of Si ({approx}0.5 at%) were conducted and showed a decrease in contact angle from 133{sup o} to 107{sup o}. The equilibrium crystal shape of Au was determined. Results showed that the presence of C at the Au surface has a measurable effect on the anisotropy of surface energy. Finally, the wetting of graphite by Pb(Ni) alloys was investigated. The results showed that contact angles of 100{sup o} and 80{sup o} coexist in the vicinity of the limit of solubility of Ni in Pb ({approx}0.17%Pb), without intermediate contact angles being present.
Date: April 25, 2001
Creator: Wynblatt, Paul
Item Type: Report
Partner: UNT Libraries Government Documents Department

Microstructural Coarsening during Thermomechanical Fatigue and Annealing of Micro Flip-Chip Solder Joints

Description: Microstructural evolution due to thermal effects was studied in micro solder joints (55 {+-} 5 {micro}m). The composition of the Sn/Pb solder studied was found to be hypereutectic with a tin content of 65--70 wt%.This was determined by Energy Dispersive X-ray analysis and confirmed with quantitative stereology. The quantitative stereological value of the surface-to-volume ratio was used to characterize and compare the coarsening during thermal cycling from 0--160 C to the coarsening during annealing at 160 C. The initial coarsening of the annealed samples was more rapid than the cycled samples, but tapered off as time to the one-half as expected. Because the substrates to which the solder was bonded have different thermal expansion coefficients, the cycled samples experienced a mechanical strain with thermal cycling. The low-strain cycled samples had a 2.8% strain imposed on the solder and failed by 1,000 cycles, despite undergoing less coarsening than the annealed samples. The high-strain cycled samples experienced a 28% strain and failed between 25 and 250 cycles. No failures were observed in the annealed samples. Failure mechanisms and processing issues unique to small, fine pitch joints are also discussed.
Date: December 1, 1998
Creator: Barney, Monica M.
Partner: UNT Libraries Government Documents Department

Selective Etching of Wide Bandgap Nitrides

Description: HIGH-DENSITY PLASMA ETCHING HAS BEEN AN EFFECTIVE PATTERNING TECHNIQUE FOR THE GROUP-III NITRIDES DUE TO ION FLUXES WHICH ARE 2 TO 4 ORDERS OF MAGNITUDE HIGHER THAN MORE CONVENTIONAL REACTIVE ION ETCH (RIE) SYSTEMS. GAN ETCH RATES EXCEEDING 0.68 MICROMETER/MIN HAVE BEEN REPORTED IN C12/H2/AR INDUCTIVELY COUPLED PLASMAS (ICP) AT -280 V DC-BIAS. UNDER THESE CONDITIONS, THE ETCH MECHANISM IS DOMINATED BY ION BOMBARDMENT ENERGIES WHICH CAN INDUCE DAMAGE AND MINIMIZE ETCH SELECTIVITY. HIGH SELECTIVITY ETCH PROCESSES ARE OFTEN NECESSARY FOR HETEROSTRUCTURE DEVICES WHICH ARE BECOMING MORE PROMINENT AS GROWTH TECHNIQUES IMPROVE. IN THIS STUDY, WE WILL REPORT HIGH-DENSITY ICP ETCH RATES AND SELECTIVITIES FOR GAN, ALN, AND INN AS A FUNCTION OF CATHODE POWER, ICP-SOURCE POWER, AND CHAMBER PRESSURE. GAN:ALN SELECTIVITIES {gt} 8:1 were observed in a C12/Ar plasma at 10 mTorr pressure, 500 W ICP-source power, and 130 W cathode rf-power, while the GaN:InN selectivity was optimized at approx. 6.5:1 at 5 mTorr, 500 W ICP-source power, and 130 W cathode rf-power.
Date: December 31, 1997
Creator: Shul, R.J.; Willison, C.G.; Bridges, M.M.; Han, J.; Lee, J.W.; Pearton, S.J. et al.
Item Type: Article
Partner: UNT Libraries Government Documents Department

IN SITU INVESTIGATION OF THE PASSIVATION OF ALLOY C22 AND OF THE PASSIVE FILMS FORMED ON ALLOY C22 IN ACIDIC ELECTROLYTES AT ROOM TEMPERATURE AND AT 90 DEGREES C

Description: The passive films formed on Alloy C22 in several acidic solutions were investigated by a combination of five in situ techniques: cyclic polarization, electrochemical impedance spectroscopy, Mott-Schottky analyses, electrochemical quartz crystal microbalance measurements, and surface enhanced Raman spectroscopy. Similar tests were conducted on unalloyed samples of nickel, chromium and molybdenum, which are the main alloying elements of Alloy C22. The results of the tests conducted on nickel, chromium, and molybdenum helped to determine the roles of these elements in the passivation of Alloy C22. In general, the corrosion resistance of C22 was superior to that of unalloyed chromium. Although chromium is an important component of the passive film on Alloy C22, the other elements figure prominently in the corrosion resistance of C22 in acidic solutions. The passivity of Alloy C22 was detrimentally affected by increasing concentrations of hydrogen ions, chloride ions, and increasing temperature. The results of this study provide understanding of the resistance/susceptibility of Alloy C22 to corrosion by the aggressive solutions that can develop inside pits and crevices.
Date: March 11, 2006
Creator: M. Miyagusuku, S. Harrington, and T. M. Devine
Item Type: Article
Partner: UNT Libraries Government Documents Department

The Proposed Yucca mOuntain Repository from a Corrosion Perspective

Description: The proposed Yucca Mountain Repository presents a familiar materials performance application that is regularly encountered in energy, transportation and other industries. The widely accepted approach to dealing with materials performance is to identify the performance requirements, to determine the operating conditions to which materials will be exposed and to select materials of construction that perform well in those conditions. A special feature of the proposed Repository is the extremely long time frame of interest, i.e. 10,000's of years and longer. Thus, the time evolution of the environment in contact with waste package surfaces and the time evolution of corrosion damage that may result are of primary interest in the determination of expected performance. Researchers at Case are part of a Department of Energy Corrosion and Materials Performance Cooperative. This team of leading scientists/engineers from major universities and national laboratories is working together to further enhance the understanding of the role of engineered barriers in waste isolation. The team is organized to address important topics: (1) Long-term behavior of protective, passive films; (2) Composition and properties of moisture in contact with metal surfaces; and (3) Rate of penetration and extent of corrosion damage over extremely long times. The work will also explore technical enhancements and seek to offer improvements in materials costs and reliability.
Date: February 10, 2006
Creator: Payer, J.H.; Agarwal, A.S.; Liu, C.C.; Pharkye, P.; Shan, X.; Shao, M. et al.
Item Type: Report
Partner: UNT Libraries Government Documents Department

THE PROPOSED YUCCA MOUNTAIN REPOSITORY FROM A CORROSIVE PERSPECTIVE

Description: The proposed Yucca Mountain Repository presents a familiar materials performance application that is regularly encountered in energy, transportation and other industries. The widely accepted approach to dealing with materials performance is to identify the performance requirements, to determine the operating conditions to which materials will be exposed and to select materials of construction that perform well in those conditions. A special feature of the proposed Repository is the extremely long time frame of interest, i.e. 10,000's of years and longer. Thus, the time evolution of the environment in contact with waste package surfaces and the time evolution of corrosion damage that may result are of primary interest in the determination of expected performance. Researchers at Case are part of a Department of Energy Corrosion and Materials Performance Cooperative. This team of leading scientists/engineers from major universities and national laboratories is working together to further enhance the understanding of the role of engineered barriers in waste isolation. The team is organized to address important topics: (1) Long-term behavior of protective, passive films; (2) Composition and properties of moisture in contact with metal surfaces; and (3) Rate of penetration and extent of corrosion damage over extremely long times. The work will also explore technical enhancements and seek to offer improvements in materials costs and reliability.
Date: February 10, 2006
Creator: UNIVERSITY, PAYER JH - CASE WESTERN RESERVE UNIVERSITY AGARWAL AS - CASE WESTERN RESERVE UNIVERSITY LANDAU U - CASE WESTERN RESERVE UNIVERSITY LIU CC - CASE WESTERN RESERVE UNIVERSITY PHARKYA P - CASE WESTERN RESERVE UNIVERSITY SHAN X - CASE WESTERN RESERVE UNIVERSITY SHAO M - CASE WESTERN RESERVE UNIVERSITY YU J - CASE WESTERN RESERVE
Item Type: Article
Partner: UNT Libraries Government Documents Department

Orientation imaging microscopy investigation of the compression deformation of a [011] ta single crystal

Description: High-purity tantalum single crystal cylinders oriented with [110] parallel to the cylinder axis were deformed 10, 20, and 30 percent in compression. The samples were subsequently sectioned for characterization using Orientation Imaging Microscopy (O&I) along two orthogonal sectioning planes: one in the plane containing [001] and [110] (longitudinal) and the other in the plane containing [1{anti 1}0] and[110] (transverse). To examine local lattice rotations, the Euler angles relative to a reference angle at the section center were decomposed to their in-plane and out-of-plane components. The in-plane and out-of-plane misorientation maps for all compression tests reveal inhomogeneous deformation everywhere and particularly large lattice rotations in the comers of the longitudinal section. Of particular interest are the observed alternating orientation changes. This suggests the existence of networks of dislocations with net alternating sign that are required to accommodate the observed rotations. Rotation maps from the transverse section are distinctly different in appearance from those in the longitudinal plane. However, the rotation maps confirm that the rotations observed above were about the [1{anti 1}0] axis. Alternating orientation changes are also observed on this section. Results will be directly compared with crystal rotations predicted using finite element methods and reviewed in light of the LLNL Multiscale Materials Modeling Program.
Date: January 8, 1999
Creator: Adams, B L; Campbell, G H; King, W E; Lassila, D H; Stolken, J S; Sun, S et al.
Item Type: Report
Partner: UNT Libraries Government Documents Department