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Properties of a boron carbide-iron ceramal

Description: Report presenting an investigation to determine the properties of a boron carbide-iron ceramal. The properties were compared to the properties of hot-pressed boron carbide. The properties evaluated were room- and elevated-temperature modulus of rupture, resistance to fracture by thermal shock, density, and oxidation characteristics.
Date: March 1950
Creator: Lidman, William G. & Hamjian, H. J.
Partner: UNT Libraries Government Documents Department

Consolidation and shaping of boron ; summary of previous work

Description: From abstract: "The deposit on the rods is in the form of a brittle uneven tube which is cracked off and subsequently pulverized to a 200-mesh powder. This report is chiefly concerned with methods of consolidating this powder and shaping it into forms required, though it also discusses to some extent other methods of shaping boron or born-rich materials."
Date: October 8, 1945
Creator: Kamm, Robert L.
Partner: UNT Libraries Government Documents Department

The Boron-Carbon System: Quarterly Report No. 1, May 1, 1960 - June 31, 1960

Description: Abstract: A definitive investigation of the boron-carbon equilibrium system is being made by X-ray diffraction, metallographic, and thermal analytical techniques. Alloys are being produced by sintering pressed powder aggregates with subsequent arc melting. Alloys have been made at two atomic percent intervals up to thirty atomic per cent carbon. In the future, higher carbon compositions are to be investigated. Techniques have been worked out for the metallographic preparation of the extremely hard and friable alloys.
Date: August 5, 1960
Creator: Elliott. Rodney P. & Van Thyne, R. J.
Partner: UNT Libraries Government Documents Department

The Boron-Carbon System: Quarterly Report No. 3, November 1, 1960 - January 31, 1961

Description: Abstract: A definitive investigation of the boron-carbon equilibrium system is being made by X-ray diffraction, metallographic, and thermal analytical techniques. On the basis of metallographic and X-ray diffraction studies it is concluded that boron carbide has a range of solubility from approximately 10 to 20 atomic per cent carbon at 1500 degrees to 2000 degrees Celsius. The melting point of the carbide-graphite eutectic has been established as 2325-2350 degrees Celsius. No reversible allotropy of the beta-rhombohedral structure has been observed. The solubility of carbon in boron is very small. The melting point of dilute carbon alloys is found to be essentially the same as that of pure boron (2040 degrees to 2050 degrees). No metallographic evidence of a three-phase reaction of dilute alloys is observed.
Date: February 6, 1961
Creator: Elliott. Rodney P.
Partner: UNT Libraries Government Documents Department

The Boron-Carbon System: Final Technical Report, May 1, 1960 - April 30, 1961

Description: Abstract: The boron-carbon equilibrium diagram has been determined by X-ray, metallographic, and thermal analysis of sintered and arc-cast alloys. A single carbide having a range of solubility from approximately 9 to 20 a/o carbon and melting congruently exists in the system. The terminal solubility of carbon in boron is 0.1-0.2a/o. The freezing reaction at the composition and melting temperature of elemental boron; there is a eutectic reaction at 29a/o carbon and 2375 degrees Celcius. No allotropy of boron was observed.
Date: June 7, 1961
Creator: Elliott. Rodney P.
Partner: UNT Libraries Government Documents Department

The Boron-Carbon System: Quarterly Report No. 2, August 1, 1960 - October 31, 1960

Description: Abstract: A definitive investigation of the boron-carbon equilibrium system is being made by X-ray diffraction, metallographic, and thermal analytical techniques. Additional baron-carbon alloys have been prepared by sintering and arc-melting compacts prepared from boron and high-purity graphite. Metallographic examinations of these alloys are in agreement with alloys previously preapred from lampblack. X-ray investigation of sintered compacts indicates that the solubility range of boron carbide extends almost to pure boron. Boron of various purities has been annealed for times up to four hours, but no structure other than beta-rhombohedral has been detected. Very high purity boron (10 ppm impurity) has been obtained for the study of allotropy and the equilibrium relationships at very dilute carbon contents.
Date: November 8, 1960
Creator: Elliott. Rodney P. & Van Thyne, R. J.
Partner: UNT Libraries Government Documents Department

Radiation Damage in Boron Carbide

Description: From introduction: "Report describing the study of radiation damage in boron carbide with an integrated thermal neutron flux of 3x10^20 neutrons/cm² in the Materials Testing Reactor (MTR)."
Date: August 18, 1953
Creator: Tucker, Charles W., Jr. & Senio, Peter
Partner: UNT Libraries Government Documents Department

Comparative Boron Isotopic Analysis

Description: S>Surface ionization results for natural boron isotopic analysis are in agreement with other recent investigations indicating a B/sup 11//B/sup 10/ atom ratio nesrer to 4.00 than the more commonly accepted value of 4.31 based on BF/ sub 3/ analysis. (auth)
Date: April 1, 1961
Creator: Goris, P.; Morgan, T. D. & Nielsen, R. A.
Partner: UNT Libraries Government Documents Department

Boron stainless steel for drop rods

Description: From introduction: "The present investigation of the properties of boron stainless steel is an outgrowth of a project started in 1947. The problem is to replace the present steel used for drop rods in the Hanford piles with a material much less subject to corrosive attack from the humid atmosphere existing at the location of the rods."
Date: September 7, 1948
Creator: Callen, A. C. & Heckman, A. L.
Partner: UNT Libraries Government Documents Department

Effect of Boron Liner on Neutron Background in Cavity

Description: Introduction: "In connection with conducting neutron experiments in a pit with earth and concrete walls, it was proposed that the background flux of neutrons might be reduced by lining the walls of the pit with a neutron absorber such as boron. To determine how much liner material would be desirable and what diminution in the neutron background could be expected, the following measurements were undertaken."
Date: January 16, 1953
Creator: Benveniste, Jack
Partner: UNT Libraries Government Documents Department

Performance of slurries of 50 percent boron in JP-4 fuel in 5-inch ram-jet burner

Description: Report presenting the performance of slurries of 50 percent boron in MIL-F-5624A grade JP-4 fuel evaluated in a 5-inch ramjet burner. Boron slurries were found to give higher heat outputs than JP-4 fuel only at fuel-air ratios above stoichiometric for JP-4 fuel. Testing found that it was also possible to determine the flow properties of particular batches of slurry before burning by flowing them through a bench system which would simulate the actual fuel system that would use the slurry.
Date: June 10, 1954
Creator: Reynolds, Thaine W. & Haas, Donald P.
Partner: UNT Libraries Government Documents Department

Preparation, Cladding, and Evaluation of Titanium-boron Dispersions

Description: This report discusses tests on the preparation and cladding of hot-pressed and pressure-bonded titanium-boron. It explores the properties of titanium-boron as a control material in reactors.
Date: June 9, 1957
Creator: Paprocki, Stan J.; Keller, Donald L.; Hodge, Edwin S.; Cunningham, George W.; Gedwill, Michael A. & Lozier, Donald E.
Partner: UNT Libraries Government Documents Department

Properties of boron/boron-nitride multilayers

Description: Boron-Nitride films are of interest for their high hardness and wear resistance. Large intrinsic stresses and poor adhesion which often accompany high hardness materials can be moderated through the use of a layered structure. Alternate layers of boron (B) and boron-nitride (BN) are formed by modulating the composition of the sputter gas during deposition from a pure B target. The thin films are characterized with TEM to evaluate the microstructure and with nanoindentation to determine hardness. Layer pair spacing and continuity effects on hardness are evaluated for the B/BN films.
Date: June 1, 1996
Creator: Jankowski, A. F.; Wall, M. A.; Hayes, J. P. & Alexander, K. B.
Partner: UNT Libraries Government Documents Department

Characterization of Boron Nitride Thin Films on Silicon (100) Wafer.

Description: Cubic boron nitride (cBN) thin films offer attractive mechanical and electrical properties. The synthesis of cBN films have been deposited using both physical and chemical vapor deposition methods, which generate internal residual, stresses that result in delamination of the film from substrates. Boron nitride films were deposited using electron beam evaporation without bias voltage and nitrogen bombardment (to reduce stresses) were characterize using FTIR, XRD, SEM, EDS, TEM, and AFM techniques. In addition, a pin-on-disk tribological test was used to measure coefficient of friction. Results indicated that samples deposited at 400°C contained higher cubic phase of BN compared to those films deposited at room temperature. A BN film containing cubic phase deposited at 400°C for 2 hours showed 0.1 friction coefficient.
Date: August 2007
Creator: Maranon, Walter
Partner: UNT Libraries

Chemical and Electronic Structure of Aromatic/Carborane Composite Films by PECVD for Neutron Detection

Description: Boron carbide-aromatic composites, formed by plasma-enhanced co-deposition of carboranes and aromatic precursors, present enhanced electron-hole separation as neutron detector. This is achieved by aromatic coordination to the carborane icosahedra and results in improved neutron detection efficiency. Photoemission (XPS) and FTIR suggest that chemical bonding between B atoms in icosahedra and aromatic contents with preservation of π system during plasma process. XPS, UPS, density functional theory (DFT) calculations, and variable angle spectroscopic ellipsometery (VASE) demonstrate that for orthocarborane/pyridine and orthocarborane/aniline films, states near the valence band maximum are aromatic in character, while states near the conduction band minimum include those of either carborane or aromatic character. Thus, excitation across the band gap results in electrons and holes on carboranes and aromatics, respectively. Further such aromatic-carborane interaction dramatically shrinks the indirect band gap from 3 eV (PECVD orthocarborane) to ~ 1.6 eV (PECVD orthocarborane/pyridine) to ~1.0 eV (PECVD orthocarborane/aniline), with little variation in such properties with aromatic/orthocarborane stoichiometry. The narrowed band gap indicate the potential for greatly enhanced charge generation relative to PECVD orthocarborane films, as confirmed by zero-bias neutron voltaic studies. The results indicate that the enhanced electron-hole separation and band gap narrowing observed for aromatic/orthocarborane films relative to PECVD orthocarborane, has significant potential for a range of applications, including neutron detection, photovoltaics, and photocatalysis. Acknowledgements: This work was supported by the Defense Threat Reduction Agency (Grant No.HDTRA1-14-1-0041). James Hilfiker is also gratefully acknowledged for stimulating discussions.
Date: December 2016
Creator: Dong, Bin
Partner: UNT Libraries