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Development, characterization, and evaluation of materials for open cycle MHD. Quarterly report, March 1977

Description: The objectives of this program are to develop, test, characterize, and evaluate materials for open-cycle, coal-fired MHD power generators. The specific immediate goals emphasize electrode and insulator materials, including: (1) testing and evaluation of the enhanced effects of alkali seed on materials in a dc electric field; (2) development and testing of improved electrodes and insulators with controlled microstructures, compositions and properties; and (3) characterization and evaluation of materials relating to both the US MHD Program and the US-USSR Cooperative Program for MHD power generators. Detailed results are presented.
Date: June 1, 1977
Creator: Bates, J.L.
Partner: UNT Libraries Government Documents Department

Visible and Infrared Absorption Spectra of Uranium Dioxide

Description: The absorption spectra for single crystal and polycrystalline UO/sub 2/ were measured between 0.6 and 15 mu at room temperature. The spectrum for UO/ sub 2/ resembles that of a typical semiconductor, opaque in the visible but transparent over a large portion of the infrared. The absorption edge is located at approximately 0.6 mu (2.0 ev). A large optical window extends from 3 to 13 mu . The absorption coefficient for single crystal UO/sub 2/ was determined between 1.5 and 15 mu . A maximum value of 57 cm/sup -1/ was measured at 1.70 mu with minimum values of 6 cm/sup -1/ at 2.75 and 8 mu . The absorption coefficient of polycrystalline UO/sub 2/ at wavelengths less than 8 mu is estimated to be ten times larger than for single crystal UO/sub 2/. (auth)
Date: September 1, 1963
Creator: Bates, J. L.
Partner: UNT Libraries Government Documents Department

Evaluation of candidate magnetohydrodynamic materials for the U-02 Phase III test

Description: As part of a cooperative U.S.--U.S.S.R. program, electrode and insulator materials tested at the Westinghouse Electrode Systems Test Facility in Pittsburgh, Pennsylvania, were evaluated. From this evaluation materials will be selected for use in the third phase of tests being conducted in the U-02 magnetohydrodynamics test facility in the Soviet Union. Electrode and insulator materials were examined with both an optical microscope and a scanning electron microscope. The cathodes were found to behave differently from the anodes; most notably, the cathodes showed greater potassium interaction. The lanthanum chromite-based electrodes (excluding those fabricated by plasma-spraying) are recommended for testing in the U-02 Phase III test. Hotpressed, fused-grained MgO and sintered MgAl/sub 2/O/sub 4/ are recommended as insulator materials. The electrode attachment techniques used in the Westinghouse Tests were inadequate and need to be modified for the U-02 test.
Date: June 1, 1978
Creator: Marchant, D.D. & Bates, J.L.
Partner: UNT Libraries Government Documents Department

Development of materials for open-cycle MHD. Quarterly report for the period ending June 1983

Description: Pacific Northwest Laboratory (PNL) is conducting an ongoing study of channel components for open-cycle, coal-fired magnetohydrodynamic (MHD) generators. Specifically, electrodes and insulators are being developed. The electrical conductivity has been measured on several compositions based on hafnium oxide, rare earth oxides, and indium oxide and on In/sub 2/O/sub 3/-SnO/sub 2/ compositions. Indium oxide at present appears to be the main constituent required for high conductivity. In the indium oxide-rare earth oxides-hafnium oxide compositions, the indium forms compounds with the other elements and is present in samples as individual grains and not as a contaminant along the grain boundary. In the In/sub 2/O/sub 3/-SnO/sub 2/ compositions, adding SnO/sub 2/ to In/sub 2/O/sub 3/ produces compositions with higher conductivity than pure In/sub 2/O/sub 3/.
Date: November 1, 1983
Creator: Marchant, D.D. & Bates, J.L.
Partner: UNT Libraries Government Documents Department

Preparation and properties of electrically conducting ceramics based on indium oxide-rare earth oxides-hafnium oxides

Description: Electrically conducting refractory oxides based on adding indium oxide to rare earth-stabilized hafnium oxide are being studied for use in magnetohydrodynamic (MHD) generators, fuel cells, and thermoelectric generators. The use of indium oxide generally increases the electrical conductivity. The results of measurements of the electrical conductivity and data on corrosion resistance in molten salts are presented.
Date: September 1, 1983
Creator: Marchant, D.D. & Bates, J.L.
Partner: UNT Libraries Government Documents Department

Development, characterization and evaluation of materials for open cycle MHD. Quarterly report for the period ending December 1978

Description: The objectives of this program are to develop, test, characterize, and evaluate materials for open-cycle, coal-fired MHD power generators. The specific immediate goals emphasize electrode and insulator materials, including: (1) testing and evaluation of the enhanced effects of alkali seed on materials in a dc electric field; (2) development and testing of improved electrodes and insulators with controlled microstructures, compositions and properties; and (3) characterization and evaluation of materials relating to both the US MHD Program and the US-USSR Cooperative Program for MHD power generators. The scope of this program encompasses the following areas: (1) reproducible laboratory testing of both ceramic and metal electrode materials and insulator materials in alkali seed/slag under dc electric current and voltages, as functions of temperature, and seed/slag composition; (2) development and fabrication of electrodes, insulators, and other related materials with controlled electrical, chemical, and physical properties, including evaluation in laboratory tests in US MHD test facilities and as part of the US-USSR testing program; and (3) characterization and evaluation of materials tested under the US-USSR and the US MHD programs including the measurement and analysis of structural, chemical, and thermophysical properties of electrodes, insulators, slag, and other related materials before and after testing. Progress is reported.
Date: June 1, 1979
Creator: Bates, J.L. & Marchant, D.D.
Partner: UNT Libraries Government Documents Department

Development, characterization and evaluation of materials for open cycle MHD. Quarterly report for the period ending September 1979

Description: The development of hafnium-rare earth oxides, with demonstrated potential for MHD hot electrode, continues at a high level. Procedures for fabricating high density ceramic compacts with uniform microstructures at temperatures below 1875K for three compositions have been developed. Bars of these materials are being fabricated for testing in the Westinghouse WESTF facility. Yttrium chromites, which have also shown potential for hot electrodes, are being fabricated into test bars by a commercial supplier. These materials are being prepared for testing in WESTF. The required electrical conductivity and thermal conductivity have been, and are being, measured for these electrode materials. The RFG air preheater refractory, tested in Montana State University's heat exchangers (Core number 1) has been characterized and evaluated. The potential mechanism for corrosive attack by the molten slag have been identified.
Date: November 1, 1979
Creator: Bates, J.L. & Marchant, D.D.
Partner: UNT Libraries Government Documents Department

Development, characterization and evaluation of materials for open cycle MHD. Quarterly report, June 1979

Description: The objectives of this program are to develop, test, characterize, and evaluate materials for open-cycle, coal-fired MHD power generators. The specific immediate goals emphasize electrode and insulator materials, including: (1) testing and evaluation of the enhanced effects of alkali seed on materials in a dc electric field; (2) development and testing of improved electrodes and insulators with controlled microstructures, compositions and properties; and (3) characterization and evaluation of materials relating to both the US MHD Program and the US-USSR Cooperative Program for MHD power generators. Progress is reported.
Date: October 1, 1979
Creator: Bates, J.L. & Marchant, D.D.
Partner: UNT Libraries Government Documents Department

Development, characterization and evaluation of materials for open-cycle MHD. Quarterly report for the period ending December 1980

Description: The development and fabrication is continuing on a graded composite electrode with a refractory HfO/sub 2/-Re/sub x/O/sub y/ surface and a HfO/sub 2/-RE/sub x/O/sub y/-In/sub 2/O/sub 3/ current leadout for testing. The electrical conductivity of some oxide current leadouts were measured, and some general conclusions made regarding effects of composition. Also measured was the electrical conductivity of some yttrium chromites doped with Mg and Ca. The characterization and evaluation of Pt-coated Cu anodes tested in AVCO's Mark VI generator using K/sub 2/SO/sub 4/ as seed was completed. Potential mechanisms for enhanced corrosion of Cu and Pt in sulfate seed are discussed. The characterization of slag removed from MSU No. 1 heat exchanger core was completed. Possible reasons for enhanced slag blocking of RFG core are considered.
Date: January 1, 1982
Creator: Bates, J.L. & Marchant, D.D.
Partner: UNT Libraries Government Documents Department

Electrochemical corrosion of lanthanum chromite and yttrium chromite in coal slag

Description: Lanthanum chromites have long been considered as electrodes for magnetohydrodynamic (MHD) generator channels. These chromites, when doped with divalent ions such as Ca, Mg or Sr, have adequate electronic and electrical conductivity (2), and melting points greater than 2500/sup 0/K. However, above approx. 1850/sup 0/K, selective vapor loss of chromium results in the formation of a La/sub 2/O/sub 3/ phase. The La/sub 2/O/sub 3/ is hydroscopic at room temperature, resulting in a large volume change and loss of mechanical integrity when exposed to H/sub 2/O. The analogous yttrium chromites have thermal and electrical properties similar to that for the lanthanum chromites. Although vapor loss of Cr results in the formation of Y/sub 2/O/sub 3/, this oxide does not hydrate. Corrosion studies of yttrium chromite compositions show that doped YCrO/sub 3/ may be a viable MHD electrode. An electrochemical corrosion study of both magnesium-doped lanthanum and yttrium chromites in synthetic coal slag electrolytes is described. Possible chemical and electrochemical degradation phenomena, as well as the relative rates of corrosion are emphasized.
Date: January 1, 1981
Creator: Marchant, D.D. & Bates, J.L.
Partner: UNT Libraries Government Documents Department

Development of materials for open-cycle magnetohydrodynamics (MHD): ceramic electrode. Final report

Description: Pacific Northwest Laboratory, supported by the US Department of Energy, developed advanced materials for use in open-cycle, closed cycle magnetohydrodynamics (MHD) power generation, an advanced energy conversion system in which the flow of electrically conducting fluid interacts with an electric field to convert the energy directly into electricity. The purpose of the PNL work was to develop electrodes for the MHD channel. Such electrodes must have: (1) electrical conductivity above 0.01 (ohm-cm)/sup -1/ from near room temperature to 1900/sup 0/K, (2) resistance to both electrochemical and chemical corrosion by both slag and potassium seed, (3) resistance to erosion by high-velocity gases and particles, (4) resistance to thermal shock, (5) adequate thermal conductivity, (6) compatibility with other channel components, particularly the electrical insulators, (7) oxidation-reduction stability, and (8) adequate thermionic emission. This report describes the concept and development of high-temperature, graded ceramic composite electrode materials and their electrical and structural properties. 47 refs., 16 figs., 13 tabs.
Date: September 1, 1986
Creator: Bates, J.L. & Marchant, D.D.
Partner: UNT Libraries Government Documents Department

Development of materials for open-cycle MHD. Quarterly report for the period ending March 1983

Description: Pacific Northwest Laboratory (PNL) is conducting an ongoing study of channel components for open-cycle, coal-fired magnetohydrodynamic (MHD) generators. Specifically, electrodes and insulators are being developed. The electrical conductivity has been measured on several compositions based on hafnium oxide, rare earth oxides, and indium oxide. Indium oxide at present appears to be the main constituent required for high conductivity. As part of the development, materials are being corrosion tested in both Montana Rosebud coal slag and potassium sulfate (K/sub 2/SO/sub 4/). The results from three coal slag tests and one K/sub 2/SO/sub 4/ test are discussed in this document.
Date: July 1, 1983
Creator: Marchant, D.D. & Bates, J.L.
Partner: UNT Libraries Government Documents Department

Development of materials for open cycle MHD. Quarterly report for the period ending March 1981

Description: The work centers around the development and fabrication of the HfO/sub 2/-RE/sub x/O/sub y/ electrodes and HfO/sub 2/-RE/sub x/O/sub y/-In/sub 2/O/sub 3/ current leadouts for testing in MHD facilities. The electrical conductivity of some potential HfO/sub 2/-RE/sub x/O/sub y/ refractory electrodes has been measured and preliminary results analyzed in relationship to structure and composition. Six potential air preheater materials, tested in the Montana State University heat exchanger, were characterized and evaluated. The potential mechanisms for corrosion/erosion are discussed. Electrochemical corrosion of platinum in molten coal slag was also measured. Possible corrosion mechanisms are discussed.
Date: January 1, 1982
Creator: Bates, J.L. & Marchant, D.D.
Partner: UNT Libraries Government Documents Department

Development of materials for open-cycle MHD. Quarterly report ending December 1982

Description: Pacific Northwest Laboratory (PNL) is conducting an ongoing study of channel components for open cycle, coal-fired magnetohydrodynamic generators. specifically, electrodes/insulators are being developed and tested. For this study, a hot-walled test channel with eight electrodes was fabricated for testing in the WESTF test facility at Westinghouse Research and Development Laboratory, Pittsburgh, Pennsylvania. The chanel is designed to operate hot on all four walls, thereby reducing the amount of condensed slag. The compositions of four of the electrodes in the test channel were based on hafnium oxide-rare earth oxides-indium oxide. The electrical conductivity has been measured on several compositions based on hafnium oxide-rare earth oxides-indium oxides. The results show that adequate conductivity may be obtained with reduced indium oxide content as long as praseodymium oxide is used as the rare earth.
Date: March 1, 1983
Creator: Marchant, D.D. & Bates, J.L.
Partner: UNT Libraries Government Documents Department