207 Matching Results

Search Results

Advanced search parameters have been applied.

Hot Isostatic Press (HIP) vitrification of radwaste concretes

Description: Properly formulated and properly ``canned`` radwaste concretes can be readily hot-isostatically-pressed (HIPed) into materials that exhibit performance equivalent to typical radwaste-type glasses. The HIPing conditions (temperature/pressure) required to turn a concrete waste form into a ``vitrified`` waste form are quite mild and therefore consistent with both safety and high productivity. This paper describes the process and its products with reference to its potential application to Idaho Chemical Processing Plant (ICPP) reprocessing wastes.
Date: December 1, 1995
Creator: Siemer, D.D.; Scheetz, B. & Gougar, M.L.D.
Partner: UNT Libraries Government Documents Department

IMPROVEMENT OF WEAR COMPONENT'S PERFORMANCE BY UTILIZING ADVANCED MATERIALS AND NEW MANUFACTURING TECHNOLOGIES: CASTCON PROCESS FOR MINING APPLICATIONS

Description: During this reporting period, the debinding and off-gassing furnace was switched from a vacuum furnace to a conventional kiln to solve the HIP can expansion problem during high temperature off-gassing, which caused disc distortion. Two 6.5 inch discs were produced. Both looked acceptable and one was machined. It was found that the disc hub section was little bit thin and micro cracks were seen along the disc radial directions.
Date: March 22, 2004
Creator: Huang, Xiaodi & Gertsch, Richard
Partner: UNT Libraries Government Documents Department

IMPROVEMENT OF WEAR COMPONENT'S PERFORMANCE BY UTILIZING ADVANCED MATERIALS AND NEW MANUFACTURING TECHNOLOGIES: CASTCON PROCESS FOR MINING APPLICATIONS

Description: In this reporting period, full disc prototype manufacturing tests continued. The disc size and HIP can problems were corrected. Unfortunately, cracking still occurred on insert interface, possibly due to oxidation film on the particle boundaries. This indicates improper off-gassing.
Date: February 27, 2004
Creator: Huang, Xiaodi & Gertsch, Richard
Partner: UNT Libraries Government Documents Department

Development of Cryogenically Microwave Lossy Ceramics with Adjustable Properties

Description: At cryogenic temperatures (below 20 K), most of the existing lossy materials become non-lossy, requiring the development of a new materials effective in these conditions. Results of an effort to develop a cryogenically lossy materials based on the AlN matrix are presented in the paper. Hot pressing with a wide range of possible lossy second phases was tried, followed by complex permitivity measurements. A promising second phase was selected, produced and evaluated under cryogenic conditions at the Thomas Jefferson National Accelerator Facility (Jefferson Lab). The developed material system allows the dielectric permitivity to be varied depending on the application requirements.
Date: July 1, 2002
Creator: Mikijeli, Biljana & Campisi, Isidoro
Partner: UNT Libraries Government Documents Department

IMPROVEMENT OF WEAR COMPONENT'S PERFORMANCE BY UTILIZING ADVANCED MATERIALS AND NEW MANUFACTURING TECHNOLOGIES: CASTCON PROCESS FOR MINING APPLICATIONS

Description: In this reporting period, the project focused on the investigations of FM material container-less HIPping, disc section examination and heat treatment, and full disc manufacture. The FM container-less HIPping resulted in either full density not being reached or reaching full density but losing the FM structure. Container HIPping seems to be necessary to consolidate the FM material. The heat treatment conducted on the 6.5 inch disc section with a WC insert caused cracking in the WC body and along the WC and H13 boundary. Two full 6.5 inch disc cutters were produced but contained defects. It is planned to produce more full disc cutters in the next quarter.
Date: May 1, 2003
Creator: Huang, Xiaodi & Gertsch, Richard
Partner: UNT Libraries Government Documents Department

IMPROVEMENT OF WEAR COMPONENT'S PERFORMANCE BY UTILIZING ADVANCED MATERIALS AND NEW MANUFACTURING TECHNOLOGIES: CASTCON PROCESS FOR MINING APPLICATIONS

Description: The project has seen quite a bit of activity in this quarter, highlighted by the fabrication of a bit insert for field testing. In addition: (1) Several alternative process techniques were attempted to prevent bloating, cracking and delamination of FM material that occurs during binder burnout. The approaches included fabrication of FM material by three pass extrusion and warm isostatic pressing of green material, slow and confined burnouts as well as, burnout of thin plate instead of rod stock. Happily, a confined burnout followed by HIPing, produced FM button inserts without bloating or delamination. (2) Four rock bit inserts were produced from FM material and are ready for use on blast hole bits in the field. (3) Six of the project participants from Michigan Technological University, Advanced Ceramic Manufacturing, and The Robbins Group visited the Superior Rock Bit Company in Minnesota and planned the field test of FM inserts.
Date: August 27, 2002
Creator: Huang, Xiaodi & Gertsch, Richard
Partner: UNT Libraries Government Documents Department

Plutonium Immobilization Form Development Interim and Final Data Report Summaries

Description: Contained within this report are summaries of the available interim and final data summary reports provided by ANSTO, ANL, LLNL, and WSRC in support of work in the Form Development activity in the Plutonium Immobilization Development and Testing Program. Milestone reports and technical papers prepared for journals or conference proceedings are not included in this list. This document covers work from about 1997 to the present. All of the following reports are available from the Plutonium Immobilization Program Document Control Center (DCC) at LLNL. In most cases, the documents can also be obtained from the libraries the originating site or from the document's authors. All samples of the various formulations discussed in the following summaries were prepared by one of four processes: Wet-milling, dry-milling, an alkoxide-nitrate process, or attritor milling. The fabrication processes differ primarily in the mixing steps. The wet milling process is the one most commonly used. It is a simple ball milling process where water is added that provides intimate mixing of the materials. The dry milling process is a worst case dry mixing process. The alkoxide-nitrate process provides for very intimate mixing and is used when equilibrium samples are desired. The attritor milling process simulates the process being developed for the Plutonium Immobilization Plant. After mixing, the subsequent calcination and consolidation steps are generally the same. Most samples were consolidated by cold pressing and sintering although some of the earlier samples or Some of the single-phase samples were prepared by hot pressing. The sample identification numbers (ID's) that are referenced in the summaries (e.g. A-0, B3-13, etc.) are described in the Sample Test Matrix (PIP-99-012 and PIP-00-016). Samples which contain both plutonium and uranium are given the designation Hf-Pu-U samples. When Ce was used as a surrogate for Pu, the designation is Hf-Ce-U. When Th was ...
Date: June 1, 2000
Creator: VanKonynenburg, R. & Ebbinghaus, B.
Partner: UNT Libraries Government Documents Department

Surface carbon films on Al-Cu-Fe quasicrystalline powders

Description: In order to study the unique properties of quasicrystals, it is necessary to form dense, homogeneous monoliths of these alloys. Unfortunately, Al-Cu-Fe quasicrystalline alloy ingots prepared by conventional casting techniques result in large scale chemical inhomogeneities which contain numerous cracks due to differential thermal contraction between the various phases during cooling. Thus a powder metallurgical approach using gas atomized (GA) powders is being pursued in order to form large samples of phase pure Al-Cu-Fe quasicrystal. A samples of specific compositions and sizes are hot isostatic pressed (HIPed) to form dense monoliths. The effects of surface contamination of GA powders, which may inhibit particle-to-particle sintering and may also increase second phase contamination in the HIPed piece, is being studied by scanning Auger microprobe (SAM), scanning electron microscopy (SEM), and transmission electron microscopy (TEM).
Date: December 31, 1996
Creator: Bloomer, T.E.; Flumerfelt, J. & Kramer, M.J.
Partner: UNT Libraries Government Documents Department

Hot isostatic press waste option study report

Description: A Settlement Agreement between the Department of Energy and the State of Idaho mandates that all high-level radioactive waste now stored at the Idaho Chemical Processing Plant be treated so that it is ready to move out of Idaho for disposal by the target date of 2035. This study investigates the immobilization of all Idaho Chemical Processing Plant calcine, including calcined sodium bearing waste, via the process known as hot isostatic press, which produces compact solid waste forms by means of high temperature and pressure (1,050 C and 20,000 psi), as the treatment method for complying with the settlement agreement. The final waste product would be contained in stainless-steel canisters, the same type used at the Savannah River Site for vitrified waste, and stored at the Idaho National Engineering and Environmental Laboratory until a national geological repository becomes available for its disposal. The waste processing period is from 2013 through 2032, and disposal at the High Level Waste repository will probably begin sometime after 2065.
Date: February 1, 1998
Creator: Russell, N.E. & Taylor, D.D.
Partner: UNT Libraries Government Documents Department

SYNTHESIS AND FABRICATION OF MO-W COMPONENTS FOR NEUTRON RESONANCE SPECTROSCOPY TEMPERATURE MEASUREMENT

Description: A Molybdenum--{sup 182}Tungsten (Mo-{sup 182}W) alloy was specified for an application that would ultimately result in the measurement of temperature and particle velocity during the steady state time following the shock loading of various materials. The {sup 182}W isotope provides a tag for the analysis of neutron resonance line shape from which the temperature may be calculated. The material was specified to have 1.8 atom percent W, with W-rich regions no larger than 1 {micro}m in size. Both the composition and W distribution were critical to the experiment. Another challenge to the processing was the very small quantity of {sup 182}W material available for the synthesis of the alloy. Therefore, limited fabrication routes were available for evaluation. Several synthesis and processing routes were explored to fabricate the required alloy components. First, precipitation of W onto Mo powder using ammonium metatungstate was investigated for powder synthesis followed by uniaxial hot pressing. Second, mechanical alloying (MA) followed by hot isostatic pressing (HIP) and warm forging was attempted. Finally, arc-melting techniques followed by either hot rolling or crushing the alloyed button into powder and consolidation were pursued. The results of the processing routes and characterization of the materials produced will be discussed.
Date: September 1, 1999
Creator: BINGERT, S.; DESCH, P. & TRUJILLO, E.
Partner: UNT Libraries Government Documents Department

A powder metallurgy approach for production of innovative radioactive waste forms

Description: The feasibility of producing a single metal-matrix composite form rather than two separate forms consisting of a cast metal alloy ingot (such as Type 316SS + Zr) and a ceramic glass-bonded zeolite Na{sub 12}(AlO{sub 2}){sub 12}(SiO{sub 2}){sub 12} has been demonstrated. This powder metallurgy approach consists of mixing the powder of the two separate waste forms together followed by compaction by hot isostatic pressing. Such a radioactive waste form would have the potential advantages of reducing the total waste volume, good thermal conductivity, stability, and surfaces with limited oxide layer formation. 5 refs., 8 figs., 2 tabs.
Date: July 1, 1997
Creator: Keiser, D.D. Jr.; Crawford, D.C. & Bhaduri, S.
Partner: UNT Libraries Government Documents Department

Processing and properties of molybdenum silicide intermetallics containing boron

Description: The processing and mechanical properties of Mo-Si-B intermetallic alloys with compositions Mo-26.7Si-7.3B and Mo-12Si-8.5B (at.%) were investigated. The first alloy consisted of the phases Mo{sub 3}Si, Mo{sub 5}Si{sub 3} (T1) and Mo{sub 5}SiB{sub 2} (T2). Attempts to extrude castings of this alloy at 1700 or 1800 C were not successful. Hot isostatic pressing of elemental powders was more promising and room temperature flexure strengths on the order of 200 MPa were reached. The second alloy with the composition Mo-12Si-8.5B could be readily cast and consisted of {alpha}-Mo inclusion in a brittle matrix of Mo{sub 3}Si and T2. A heat treatment of 1 day at 1600C in vacuum improved the room temperature strength and fracture toughness. Values on the order of 500 MPa and 10 MPa m{sup 1/2}, respectively, were obtained. Consistent with ductile phase toughening, limited plastic deformation as well as debonding of the {alpha}-Mo inclusions were seen on fracture surfaces.
Date: November 1, 1998
Creator: Schneibel, J.H.; Liu, C.T.; Heatherly, L. Jr. & Carmichael, C.A.
Partner: UNT Libraries Government Documents Department

Friction and wear behavior of in-situ reinforced silicon nitride. Final report

Description: Specimens of in-situ-reinforced silicon nitride (ISRSH) have been wear tested in lubricated, reciprocating, sliding motion against a silicon nitride counterface. Only mild wear of the ISRSN was observed at contact pressures up to 4.8 GPa at an average sliding velocity of 0.3 m/s. At 0.6 m/s, a wear mode transition was observed in ISRSN at 4.2 - 4.4 GPa. In comparison, the wear mode transition in silicon carbide whisker reinforced silicon nitride at both velocities was evident at about 2.2 - 2.4 GPa. Scanning electron microscopy of the ISRSN wear surfaces revealed the presence of a 40 pm thick debris layer on the mild wear tracks. The ISRSN wear mode transition response indicated a potential for an improved wear resistance in this material as compared to whisker reinforced silicon nitride.
Date: October 1, 1995
Creator: Yust, C.S.
Partner: UNT Libraries Government Documents Department

Alternative processing methods for tungsten-base composite materials

Description: Tungsten composite materials contain large amounts of tungsten distributed in a continuous matrix phase. Current commercial materials include the tungsten-nickel-iron with cobalt replacing some or all of the iron, and also tungsten-copper materials. Typically, these are fabricated by liquid-phase sintering of blended powders. Liquid-phase sintering offers the advantages of low processing costs, established technology, and generally attractive mechanical properties. However, liquid-phase sintering is restricted to a very limited number of matrix alloying elements and a limited range of tungsten and alloying compositions. In the past few years, there has been interest in a wider range of matrix materials that offer the potential for superior composite properties. These must be processed by solid-state processes and at sufficiently low temperatures to avoid undesired reactions between the tungsten and the matrix phase. These processes, in order of decreasing process temperature requirements, include hot-isostatic pressing (HIPing), hot extrusion, and dynamic compaction. The HIPing and hot extrusion processes have also been used to improve mechanical properties of conventional liquid-phase-sintered materials. Results of laboratory-scale investigations of solid-state consolidation of a variety of matrix materials, including titanium, hafnium, nickel aluminide, and steels are reviewed. The potential advantages and disadvantages of each of the possible alternative consolidation processes are identified. Postconsolidation processing to control microstructure and macrostructure is discussed, including novel methods of controlling microstructure alignment.
Date: December 31, 1995
Creator: Ohriner, E.K. & Sikka, V.K.
Partner: UNT Libraries Government Documents Department

Age hardening in rapidly solidified and hot isostatically pressed beryllium-aluminum-silver alloys

Description: Three different alloys of beryllium, aluminum and silver were processed to powder by centrifugal atomization in a helium atmosphere. Alloy compositions were, by weight, 50% Be, 47.5% Al, 2.5% Ag, 50% Be, 47% Al, 3% Ag, and 50% Be, 46% Al, 4% Ag. Due to the low solubility of both aluminum and silver in beryllium, the silver was concentrated in the aluminum phase, which appeared to separate from the beryllium in the liquid phase. A fine, continuous composite beryllium-aluminum microstructure was formed, which did not significantly change after hot isostatically pressing at 550 C for one hour at 30,000 psi argon pressure. Samples of HIP material were solution treated at 550 C for one hour, followed by a water quench. Aging temperatures were 150, 175, 200 and 225 C for times ranging from one half hour to 65 hours. Hardness measurements were made using a diamond pyramid indenter with a load of 1 kg. Results indicate that peak hardness was reached in 36--40 hours at 175 C and 12--16 hours at 200 C aging temperature, relatively independent of alloy composition.
Date: July 1, 1995
Creator: Carter, D.H.; McGeorge, A.C.; Jacobson, L.A. & Stanek, P.W.
Partner: UNT Libraries Government Documents Department

Manufacture of die casting dies by hot isostatic pressing. CRADA final report

Description: The reason for this Cooperative Research and Development Agreement (CRADA) between the Oak Ridge National Laboratory (ORNL) and Doehler-Jarvis was to investigate the manufacture die-casting dies with internal water-cooling lines by hot-isostatic pressing (HIPing) of H13 tool steel powder. The use of HIPing will allow the near-net-shape manufacture of dies and the strategic placement of water-cooling lines during manufacture. The production of near-net-shape dies by HIPing involves the generation of HIPing diagrams, the design of the can that can be used for HIPing a die with complex details, strategic placement of water-cooling lines in the die, computer modeling to predict movement of the water lines during HIPing, and the development of strategies for placing water lines in the appropriate locations. The results presented include a literature review, particle analysis and characterization of H13 tool steel powder, and modeling of the HIPing process.
Date: September 1, 1998
Creator: Viswanathan, S.; Ren, W.; Luk, K. & Brucher, H.G.
Partner: UNT Libraries Government Documents Department

Development of oxide fibrous monolith systems.

Description: Fibrous monolithic ceramics generally have a cellular structure that consists of a strong cell surrounded by a weaker boundary phase [1-5]. Fibrous monoliths (FMs) are produced from powders by conventional ceramic fabrication techniques, such as extrusion [1,2]. When properly engineered, they exhibit fail gracefully [3-5]. Several compositions of ceramics and cermets have been processed successfully in fibrous monolithic form [4]. The most thoroughly investigated fibrous monolith consists of Si{sub 3}N{sub 4} cells and a BN cell-boundary phase [3-5]. Through appropriate selection of initial powders and extrusion and hot-pressing parameters, very tough final products have been produced. The resultant high toughness is due primarily to delamination during fracture along textured platelike BN grains. The primary objectives of our program are to develop: (1) Oxide-based FMs, including new systems with improved properties; (2) FMs that can be pressureless sintered rather than hot-pressed; (3) Techniques for continuous extrusion of FM filaments, including solid freeform fabrication (SFF) for net-shape fabrication of FMs; (4) Predictive micromechanical models for FM design and performance; and (5) Ties with industrial producers and users of FMs.
Date: March 2, 1999
Creator: Goretta, K. C.
Partner: UNT Libraries Government Documents Department

Microstructure and properties of IN SITU toughened silicon carbide

Description: A silicon carbide with a fracture toughness as high as 9.1 MPa.m1/2 has been developed by hot pressing b-SiC powder with aluminum, boron, and carbon additions (ABC-SiC). Central in this material development has been systematic transmission electron microscopy (TEM) and mechanical characterizations. In particular, atomic-resolution electron microscopy and nanoprobe composition quantification were combined in analyzing grain boundary structure and nanoscale structural features.
Date: May 1, 2003
Creator: De Jonghe, Lutgard C.; Ritchie, Robert O. & Zhang, Xiao Feng
Partner: UNT Libraries Government Documents Department

IMPROVEMENT OF WEAR COMPONENT'S PERFORMANCE BY UTILIZING ADVANCED MATERIALS AND NEW MANUFACTURING TECHNOLOGIES: CASTCON PROCESS FOR MINING APPLICATIONS

Description: During this reporting period, we mainly focused on solving the disc distortion problem that was encountered in the last quarter. A slower heating rate during off-gassing was tested to reduce the HIPping can expansion. However, slight expansion still occurred. Two 6.5 inch discs were produced with many defects. One was made of H13 powder only and the other was made of H13 powder with WC inserts. It was believed that the defects were caused by the slight expansion of the HIP can during the elevated temperature off-gassing and a vacuum leak in the HIPping can.
Date: March 18, 2004
Creator: Huang, Xiaodi & Gertsch, Richard
Partner: UNT Libraries Government Documents Department

IMPROVEMENT OF WEAR COMPONENT'S PERFORMANCE BY UTILIZING ADVANCED MATERIALS AND NEW MANUFACTURING TECHNOLOGIES: CASTCON PROCESS FOR MINING APPLICATIONS

Description: FM Material was HIPped at 1200 C under 30 ksi. Full density was achieved. This material presents average Vicker's hardness of 1068 and fracture toughness of 10.05 MPa m{sup 1/2} in the fiber parallel direction and average Vicker's hardness of 987 and fracture toughness of 9.52 MPa m{sup 1/2} in the fiber perpendicular direction. Binder burnout of larger FM specimen (0.865 inches in diameter and 1.25 inches in length) was found very difficult. Large cracks and delamination appeared on the specimen's surface and interior even with a very slow burnout rate of 0.1 C/min was used.
Date: June 12, 2002
Creator: Huang, Xiaodi & Gertsch, Richard
Partner: UNT Libraries Government Documents Department