DOCSLIB.ORG

METALS Aid CERAMICS DIVISION

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
METALS Aid CERAMICS DIVISION -s-- r . Z Ls> > ORNL-4870 METALS aid CERAMICS DIVISION Annual Progress Report Period Ending June 30, 1973 "1 BLANK PAGE t Printed in the Untied States c* Amtfitt. Available from Nation*) Technical information Service U.S. Department of Commerce 5285 Port Royal Road. Springfield, Virginia 22151 Price: °rtnwd Copy $5.45; Micro!*!* S0.9S • ~ • Thit report was prepared as an account of work sponsored by the United Statas Government. Neither the United Statas nor the United States Atomic Energy Commission, nor any of tfc*ir employees, nor any of their contractors, subcontractors, or their employees, rnakat afty warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness or usefulness of any information, apparatus, product or process disclosed, or represents that m use would not infringe privately owned rights. ORNL-4870 UC 25 - Materials Contract No. W-74C5-«ng-26 METALS ANO CER'«MICS DIVISION ANNUAL PROGRESS REPORT for Period Endtnf June 30.1973 j. H Frye, Jr., Director* J. E. Cunninohem. Associate Director G. M. Adamson. Jr. C. J. McHar«uc P Patriarca i. R. Weir. Jr.* Compiled and Edited by Sigfred Petef too 'Rtwid June 30.1973. preawtt Uwwerutv o* fN©w Owieon Director. -NOTlCI OCTOBER 1973 OAK RlOGE NATIONAL LABORATORY O* R«ie*. Ttmnw 37830 optr»t«dbv UNION CARBIDE CORPORATION for th« U S ATOMIC ENERGY COMMISSI 0\ amim Reports prtviously issued in this series are as follows: ORNL 28 Period Ending March 1, 1948 ORNL 69 Period Ending May 31. 1948 ORNL407 Period Ending July 31. 1949 ORNL 511 Period Ending October 31, 1949 ORNL 583 Period Ending January 31, 1950 ORNL 754 Period Ending April 30. 1950 ORNL 827 Period Ending July 31. 1950 ORNL QiQ Period Ending October 31. 1350 ORNLC87 Period Ending January 31. 1951 ORNL 1033 Period Ending April 30, 1951 ORNL 1108 Period Ending July 31. 1951 ORNL -1161 Period Ending October 31. 1951 OANL-1367 Period Ending January 31. 1952 ORNL 1302 Period Ending April 30. 1952 ORNL 1366 Period Ending July 31. 1952 ORNL 1437 Period Ending October 31. 1952 ORNL 1503 Period Ending January 31. 1953 ORNL-1551 Period Ending April 10.1953 ORNL 1625 Period Ending October 10. 1953 ORNL 1727 Period Ending April 10. 1954 ORNL 1675 Period Ending October 10. 1954 ORNL 1911 Period Ending April 10.1955 ORNL 1938 Period Ending October ;0.1955 ORNL 2080 Period Ending April 10. 1956 ORNL 2217 Period Ending October 10. 1956 ORNL-24>* Period Ending October 10, 1957 ORNL 2632 Period Ending October 10. 1956 ORNL 2839 Period Ending September 1,1959 ORNL 2988 Period Ending July 1.1960 ORNL31A0 Period Ending May 31. 1961 ORNL 3313 Period Ending May 31. 1962 ORNL 3470 Period Ending May 31.1963 ORNL 3670 Per 3d Ending June 30. 1964 ORNL 3870 Period Ending June 30. 1965 ORNL 3970 Period Ending June 30. 1966 ORNL 4170 Period Ending June 30. 1967 ORNL 4370 Period Ending June 30. 1968 ORNL 4470 Period Ending June 30. 1969 ORNL 4570 Period Ending June 30. 1970 ORNL 4770 Period Ending June 30. 1971 ORNL 4820 Period Ending June 30. 1972 Contents FOREWORD ix SUMMARY xi PARTI. FUNDAMENTAL PROGRAMS 1. CRYSTAL PHYSICS 1 Metal Oxide-Metal Binary and Ternary Eutectics 1 Growth of Ternary Metal-Metai Oxide Eutectics 2 Eutectk Solidification in Binary and Ternary Metal-Metal Oxide Systems 2 Crystal Growth of Oxides by CzochraJski and Edge-Defined Film-Fed Methods 2 Bridgman-Stockbarger Growth of Single-Crystal BaF2 and BaF3 Doped with 1 at. % La 2 SrClj Crystal Containing " * Es 2 2 Electron Paramagnetic Resonance of **Bk** in Th03 Single Crystals 3 Zero-Field Splittings of Gd* andCm* inCeO, artdTh02 3 HydrothermaJ Studies of Quart/ 3 2. DEFORMATION OF CRYSTALLINE SOLIDS 4 The Nature of the Limitations or'Second-Law Determinations of Solution Thermodynamics 4 A Computer Program for the Reduction of Diffuse X-Ray Data from Solid Solutions 4 Fracture Mechanism in Precipitation-Hardened BCC Alloys 4 3. DIFFUSION IN SOUDS 7 Rele -ance of Tracer Diffusion Experiments to Problems in Nuclear Systems 7 Cation Self-Diffusion in Rutile 7 Effect of Dislocations on Self-Diffusion of Uranium in UO} Single Crystals , 7 Diffusion Under High Pressures 8 Tracer Self-Diffusion in Fe 17 wt %Cr 12 wt % Ni Austenitic Alloy 8 The Volume Diffusion of Carbon in F< 17 wt % Cr- 12 wt % Ni Austeniiic Alloy 8 Thermotransporf of Cadmium and Thallium in Sodium and Potassium Chlorides 9 Binary Intrinsic Diffusk** and Interdtffusion in Vanadium-Titanium Solid Solutions 9 4. ELECTRON MICROSCOPY , 10 Radiation-Induced Strengthening and Embrittlemem in Aluminum 10 iii IV Reply to "Comments on "On the Question of Void Formation in Neutron Irradiated Zirconium' " 10 Ei'ft :t of Silicon on Void Formation in Aluminum 11 Eff< cts of Solute Interstitial Elements on Swelling of Si^inkrss Steel 11 A High-Voltage Electron Microscope Study of the Effects of Preinjected Helium on Electron Damage in Aluminum 11 Electron Irradiation Damage in Titanium 12 Effect of Purity on Loop Formation in Aluminum and Nickel 12 Detect Structure of Neutron-irradiated Boron Carbide 12 Nucleation of Voids in Solids Containing Excess Vacancies, lnterstitials, and Helium Atoms 12 Reply to Comment on Some Calculations of Vacancy Characteristics in Substitutional Alloys 13 Nearest Neighbor Pair Models for Solution 13 Reply to Comments on *The Energy Stored in Porycrystalline Copper Deformed at Room Temperature" - More Details of the Single-Step Isoperibot Deformation Calorimeter 13 The Efficiency of Energy Storage During Plastic Deformation of he>;als 13 Creep Properties ot'CVD Tungsten 14 5. FUNDAMENTAL CERAMICS RESEARCH 15 Observation of Lattice and Giatn Boundary Dislocations in U02 Deformed at High Temperatures 15 Optical Absorption i.i Deformed CaF2 15 Redox Equilibria in Molten Uranium Dioxide 15 Synthesis. Structure, and Properties of Titaniumdi) Tetracrdoroaluminate 16 Electronic Absorption Spectra of P!atinum(II) Centers in Liquid Alkali Metal Chlorides 16 6. FUNDAMENTAL PHYSICAL METALLURGY 17 Phase Transformations in U-Nb-Zr and U-Tt Alloys 17 Texture Inhomogeneities in Cold-Rolled Niobium 17 Dispersion Hardening of Aluminum 17 Structural Effects on Radiation Damage 18 7. PHYSICAL PROPERTY RESEARCH 19 Apparatus Development 19 improved Linear Heat Flow Apparatus 19 Electrical Resistivity Measurements 19 Computerized Data Acquisition 19 Heat Flow Analysts 20 Transport in Metals 20 Aluminum 20 Platinum aid Lead 21 Chromium ? I Lattice Heat Transport in Alkali Halides 21 Coefficient of Thermal Expansion of Nickel 21 Applied Research 21 8. SUPERCONDUCTING MATERIALS 23 Measurement of Critical Bulk and Surface Current Densities in Type II Superconductor* in the Mixed State 23 V Effects of Interstitial Ox.'gen on the Superconductivity of Niobium 23 Annealing. Long-k*nge Order, and Supcrconducnnc Transition Temperature in the V,Ga A-i5 Compound 24 A Low-Temperature X-Ray lnvestv - ion of Technetium and the Tc-Mo A-15 Compound 24 Critical Current Densities in Sputter-Deposited Nb-Al-Ge 24 Thermodynamic Properties of Zirconium-Cadmium and Certain Other Solid Solutions 24 Superconducting Materials Technology for Power Transmission 25 9. SURFACE PHENOMENA 26 Oxidation of Uranium-Base Alloys 26 The Mechanical Properties of T^o Uranium Alleys sr.d Their Role in :hc Oxidation of the Alloys 26 The Oxidation of U-14 at. % Zx Between 700 and 900CC 26 Oxidation of Refractory Metal Alloys 26 Diffusion Studies 27 >0. TriEORETKTAL RESEARCH 28 KKR Band Structure Calculations for Complex Crystals 28 Density of States Expressed as Continued Fraction of Matrices: Application to Disordered Systems 28 Self-Consistent Cluster Theories of Disordered Alloys 2fc Problems in Strong Scattering Binary Alloy* 28 Charged Impurity Drift and Dispersion in Di*crete Media 29 Auger Catalog Calculated Transition Energies Listed by Energy and Element 29 Diffusion of Vacancies Near Faulted Dislocation Loops in Aluminum 29 Electronic States o( Multilayer Graphite 29 Observation of High-Energy Excited States in Graphite 29 A Combined Korrinfa-Kohn-Rostoker- Discrete Variational Method for the Electronic Structure of Crystals and Molecules with General Potentials 30 A Combined Multiple-Scattering-Discrete-Variationa! Method for the Molecular Ouster Problem 50 Effects of Thermcelastic Properties on Void Formation in Hexagonal Metals 30 Equilibrium Shape of a Prismatic Dislocation Loop 31 II. X-RAY DIP FRACTION 32 Routine Analyses 32 Lattice Expansions of Boron Carbides 32 Crystal Structure of a Hypostoichiometric Boron Carbide 33 Models of the 7* St ucture in Uranium-Base BCC Alloys 33 The Short-Range Structure of Titanium and Zirconium BCC Solid Solutions 34 Thermally Excited Fc-bidden Reflections 34 Structural and Dynamical Properties of Neutron-Irradiated Quartz and Noncrystalltne SiOj 34 Optimization of the Kratky Small-Angle X-Ray Scattering Collimation System Parameters , 35 Inelastic Resonance Emission o( X Rays: Anomalous Scattering Associated with Anomalous Dispersion 35 VI Strengthening and Fracture of Ta. Nb. Mo. and W Binary Solid Solutions with Short-Range Order 35 Development of High-Sensitivity X-Ray Fluorescence for Analysis of Trace Elements 36 Short-Range Order with Large Atomic Displacements in Niobium-Vanadium Alloys 36 PART II. SPACE POWER TECHNOLOGY 12. HIGH-TEMPERATURE ALLOYS FOR ISOTOPiC HEAT SOURCES 37 Development of »ndium-Base Alloys 37 Development of Platinum-Base Alloys 37 Iridium Purification and Scrap Recycle 38 Special Problems and Consulting 38 13. CURIUM-244 COMPATIBILITY TESTING 39 14. IRIDIUM FABRICATION 41 Iridium Sheet Development 41 Preparation of Compacts for Melting 41 Electron-Beam Melting and Casting 41 Sheet Roiling 42 Iridium Purification 43 15. PHYSICAL METALLURGY OF HEAT-SOURCE CONTAINMENT MATERIALS 45 Structure and Medianical Properties of Internally Oxidized Ta-8% W-2% Hf (T-l 11) Alloy 45 Low-Pressure Oxidation and Tensile Pr->perties of Oxygen-Contaminated T-l 11 *5 Mechanical Properties and Interstitial Contamination in a Molybdenum-Base Alloy, TZM 46 Effects of Exposure to Oxygen and Graphite on the Physical and Mechanical Properties of Iridium and Iridium Afloys 46 Special Problems and Consulting 46 16.
Load more

Recommended publications
  • Superhard and Superconducting B6C
    Superhard and Superconducting B6C Kang Xia a, Mengdong Ma b, Cong Liu a, Hao Gao a, Qun Chen a, Julong He b, Jian Sun a,*, Hui-Tian Wang a, Yongjun Tian b, and Dingyu Xing a a National Laboratory of Solid State Microstructures, School of Physics and Collaborative Innovation Center of Advanced Microstructure, Nanjing University, Nanjing 210093, China b State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004, China ABSTRACT Crystal structure searching and ab initio calculations have been used here to explore low-energy structures of boron carbides under high pressure. Under pressures of 85–110 GPa, a metastable B6C with R3 m symmetry is found to be energetically more stable than the mixture of previous B4C and elemental boron. This B6C is a rhombohedral structure and contains mooncake-like B24 clusters with stuffing of C2 pairs. The mechanical and dynamical stabilities of this structure at ambient pressure are confirmed by its elastic constants and phonon dispersions. The bulk modulus and shear modulus of this newly predicted B6C at ambient pressure reach high values of 291 GPa and 272 GPa, respectively. The Vickers hardness is calculated to be around 48 GPa, and its melting temperature at ambient pressure is estimated to be around 2500 K, indicating that this metastable B6C is a potential superhard material with very good thermal stability. Interestingly, this superhard B6C structure is also found to be superconducting and its superconducting critical temperature (Tc) is evaluated to be around 12.5 K at ambient pressure by electron-phonon coupling. * Corresponding author. E-mail address: [email protected] 1.
    [Show full text]
  • Volumetric Determination of Boron in Boron Carbide V
    B. A. R. C.-1017 ei GOVERNMENT OF INDIA ATOMIC ENERGY COMMISSION VOLUMETRIC DETERMINATION OF BORON IN BORON CARBIDE V. K. Manchanda and M. S. Subramanian Radiochemistry Division BHABHA ATOMIC RESEARCH CENTRE BOMBAY, INDIA 1979 B. A. R.C.-1017 GOVERNMENT OF INDIA ATOMIC ENERGY COMMISSION U erf < ffl VOLUMETRIC DETERMINATION OF BORON IN BORON CARBIDE by V.K. Manchanda and M. S. Subramantan Radlochernlstry Division BHABHA ATOMIC RESEARCH CENTRE BOMBAY, INDIA 1979 INIS Subject Category : Bll Descriptor a : BORON CARBIDES BORON QUANTITATIVE CHEMICAL ANALYSIS TITRATION ACCURACY ABSTRACT Boron carbide is used for oontrol rods and as a shielding material In nuclear reactors. As such, the boron carbide must conform to rigid chemical specifications. Impurities present have a significant effect on the life time of the control rods under conditions of high temperature and i neutron flux. Therefore, methods for the accurate determination of the various constituents in boron carbide is of utmost importance. This-report discusses p\volumetric procedure for i •_ . •' i : ((.•>;•" ••%. the, determination of boron content In boron carbide/ '•••>',••. A VOLtCIKTRIC DET3SIINATI0N 0? BCRON IN BORON CAR3IDE by V.K. Jfenchanda and M.S. Subramanian IU7R0DVCT10N Boron carbide is an important nuclear material a.3 it is used in nuclear reactors for control rods and as a shielding material « Preparation of boron carbide yields a product often contaminated with either unreacted carbon or boric acid. These impurities affect the physical, chemical and neutron absorption properties of the material, Particularly under conditions of high temperature and neutron flux in a reactor, tlie life time of the control rods depends on its composition.
    [Show full text]
  • The Formation and Reactivity of I BORON CARBIDE and Related
    University of Plymouth PEARL https://pearl.plymouth.ac.uk 04 University of Plymouth Research Theses 01 Research Theses Main Collection 1970 The Formation and Reactivity of BORON CARBIDE and related materials JONES, JAMES ALFRED http://hdl.handle.net/10026.1/1880 University of Plymouth All content in PEARL is protected by copyright law. Author manuscripts are made available in accordance with publisher policies. Please cite only the published version using the details provided on the item record or document. In the absence of an open licence (e.g. Creative Commons), permissions for further reuse of content should be sought from the publisher or author. The Formation and Reactivity of I BORON CARBIDE and related materials A Thesis presented for the Research Degree of DOCTOR OF PHILOSOPHY of the COUNCIL FOR NATIONAL ACADEMIC AWARDS London by JAMES ALFRED JONES Department of Chemistry Plymouth Polytechnic Plymouth, Devon- February^ 1970o F'.V flCCH. i'iC. 1 CLASS, T Shi LJl JoH 13' ABSTRACT 1 The formation of boron carbide, (CBC)*B^^0*^(3^0 is re• viewed with special reference to newer production methods and fabrication techniques. Its crystal structure and the nature of its bonding are discussed in relation to those of other borides and carbides. Information so far available on the sintering of this material is summarised in relation to its reactivity. Sintering into monolithic compoaentBcan only be achieved by hot pressing at pressures between 200 and 300 Kgcm'^ and at temperatures above 2000°C preferably at about 2,300^0 for the most rapid achievement of theoretical density, i.e.
    [Show full text]
  • The 5-Th Element a New High Pressure High Temperature Allotrope
    The 5-th element A new high pressure high temperature allotrope Von der Fakultät für Chemie und Geowissenschaften Der Universität Bayreuth zur Erlangung der Würde eines Doctors der Naturwissenschaften -Dr. rer. nat.- Dissertation vorgelegt von Evgeniya Zarechnaya aus Moskau (Russland) Bayreuth, April 2010 TABLE OF CONTENTS SUMMARY................................................................................................................................................... 1 ZUSAMMENFASSUNG.............................................................................................................................. 3 1 INTRODUCTION....................................................................................................................... 6 1.1 History of the discovery of boron................................................................................................... 6 1.2 Basic chemistry and crystal-chemistry of boron........................................................................... 7 1.3 Boron in natural systems ................................................................................................................ 9 1.4 Physical properties of boron and its application ........................................................................ 12 1.5 Boron at high pressure.................................................................................................................. 15 1.6 Experimental techniques and sample characterization ............................................................
    [Show full text]
  • Processing of Reaction-Bonded B4C–Sic Composites in a Single-Mode Microwave Cavity
    Available online at www.sciencedirect.com CERAMICS INTERNATIONAL Ceramics International 39 (2013) 1215–1219 www.elsevier.com/locate/ceramint Processing of reaction-bonded B4C–SiC composites in a single-mode microwave cavity Anthony Thuaulta,n, Sylvain Marinela,b, Etienne Savarya,c, Romain Heugueta, Se´bastien Saunierc, Dominique Goeuriotc, Dinesh Agrawalb aCRISMAT Laboratory UMR 6508 CNRS-ENSICAEN-UCBN, 6 Boulevard du Mare´chal Juin, 14050 Caen Cedex, France bMaterials Research Institute, Materials Research Laboratory Building, The Pennsylvania State University, University Park, PA 16802, USA cDe´partement Me´canique et Proce´de´s d’e´laboration, Centre des Sciences des Mate´riaux et des Structures, Ecole Nationale Supe´rieure des Mines de Saint- Etienne, 42023 Saint-Etienne Cedex 2, France Received 5 July 2012; received in revised form 16 July 2012; accepted 16 July 2012 Available online 24 July 2012 Abstract In this study, the reaction sintering of boron carbide, which consists in doing reactive infiltration of molten silicon throughout a porous sample made of B4C and carbon graphite was investigated. Thus, it has been shown that a single-mode microwave cavity can be successfully used to produce reaction-bonded B4C–SiC composite. A specific package, consisting of a SiC based susceptor and a boron nitride based insulating container, was used to heat up the B4C–Si system using a single-mode microwaves cavity under an Ar–H2 atmosphere. Pore-free B4C–SiC composite successfully produced consists of a mixture of B4C and polygonal shaped b-SiC within a residual silicon matrix. The indentation technique permits to determine mechanical properties of the samples which are compared to those obtained conventionally.
    [Show full text]
  • Nitrogen Containing Carbon Nanofibers As Non-Noble Metal Cathode Catalysts In
    Nitrogen Containing Carbon Nanofibers as Non-Noble Metal Cathode Catalysts in PEM and Direct Methanol Fuel Cells Dissertation Presented in Partial Fulfillment of the Requirements for the Degree Doctor of Philosophy in the Graduate School of The Ohio State University By Elizabeth Joyce Biddinger, B.S.ChE Graduate Program in Chemical Engineering * * * * The Ohio State University 2010 Dissertation Committee: Professor Umit S. Ozkan, Advisor Professor Jeffrey Chalmers Professor Stuart Cooper Copyright by Elizabeth Joyce Biddinger 2010 ABSTRACT PEM and direct methanol fuel cells (DMFC) have great potential for use as alternative fuel energy conversion devices. Before this potential can be realized, however, performance improvements must be made and material costs need to be reduced. The limiting reaction in the PEMFCs and DMFCs is the oxygen reduction reaction (ORR), which occurs at the cathode. In an attempt to improve the reaction kinetics, substantial loadings of Pt catalysts are required on the cathode. This significantly increases the overall cost of the fuel cell. Also, in DMFCs, methanol crossover from the anode allows for competing reactions at the cathode catalyst to occur, reducing the power output of the fuel cell further. As the demand for fuel cells increase, the demand for Pt will far outpace the supply of Pt. Replacements studied for Pt cathode catalysts include Pt alloys, other noble metals, chalcogenides and nitrogen-containing carbons. Nitrogen-containing carbons made from simple precursors can provide an economical replacement to Pt catalysts. Before this can be realized, improvements in the activity and selectivity of the nitrogen- containing carbons need to occur. ii The work presented here involves the study of nitrogen-containing carbon nanostructures (CNx) as ORR catalysts for PEMFCs and DMFCs.
    [Show full text]
  • Material Development for India's Nuclear Power Programme
    Sadhan¯ a¯ Vol. 38, Part 5, October 2013, pp. 859–895. c Indian Academy of Sciences Material development for India’s nuclear power programme AKSURI Materials Group, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085, India e-mail: [email protected] Abstract. The area of materials research has registered a phenomenal growth in the recent years, assiduously accepting and assimilating ideas, concepts and analyti- cal as well as experimental methodologies and techniques form almost all scientific disciplines, thereby demonstrating its remarkably multidisciplinary and interdiscipli- nary character. The focus of the materials programme of this centre is to provide materials, processes and processing solutions to the emerging needs of evolving indigenous nuclear energy systems by proactive research and development on a con- tinuing basis. The initial stage of our activities was formulated around three stage Indian nuclear power programme. In stage I, material issues related to in-core mate- rials with emphasis on development of fabrication routes of zirconium alloys for structural application were addressed. Subsequently the thrust areas were develop- ment and characterization of mixed oxide fuel, advanced zirconium alloys, structural steels, superalloys, neutron absorber materials based on boron carbides and borides, and shape memory alloys. The research was useful for in-service performance evalu- ation, safety assessment, residual life estimation and life extension of nuclear reactors built during stage I i.e., PHWRs and BWRs. It also included developments which would permit rapid expansion of nuclear power initially through fast breeder reactor based on mixed oxide fuel and later based on metallic fuels. For the 3rd stage, multi- layer coatings, graphite coolant tube, BeO, refractory metals and alloys, heat-treated zirconium alloys are being developed for CHTR, ADSS and AHWR.
    [Show full text]
  • Structural Stability and Mechanism of Compression
    Structural stability and mechanism of compression of stoichiometric B13C2 up to 68GPa Irina Chuvashova, Elena Bykova, Maxim Bykov, Volodymyr Svitlyk, Leonid Dubrovinsky, Natalia Dubrovinskaia To cite this version: Irina Chuvashova, Elena Bykova, Maxim Bykov, Volodymyr Svitlyk, Leonid Dubrovinsky, et al.. Structural stability and mechanism of compression of stoichiometric B13C2 up to 68GPa. Scientific Reports, Nature Publishing Group, 2017, 7, 9 p. 10.1038/s41598-017-09012-8. hal-01691833 HAL Id: hal-01691833 https://hal.archives-ouvertes.fr/hal-01691833 Submitted on 24 Jan 2018 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. www.nature.com/scientificreports OPEN Structural stability and mechanism of compression of stoichiometric B13C2 up to 68GPa Received: 15 March 2017 Irina Chuvashova1,2, Elena Bykova 2,3, Maxim Bykov2, Volodymyr Svitlyk 4, Accepted: 14 July 2017 Leonid Dubrovinsky2 & Natalia Dubrovinskaia1 Published: xx xx xxxx Boron carbide is a ceramic material with unique properties widely used in numerous, including armor, applications. Its mechanical properties, mechanism of compression, and limits of stability are of both scientifc and practical value. Here, we report the behavior of the stoichiometric boron carbide B13C2 studied on single crystals up to 68 GPa.
    [Show full text]
  • LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, E.G. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE {(Roofi
    CPC - C04B - 2021.08 C04B LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE {(roofing granules E04D 7/005)}; CERAMICS (devitrified glass-ceramics C03C 10/00); REFRACTORIES; TREATMENT OF NATURAL STONE Definition statement This place covers: Chemical aspects of the processing of lime, magnesia or dolomite and of molten slag. Compositional aspects of: • inorganic binders, such as hydraulic cements ; • mortars, concrete and artificial stone, e.g. the choice of fillers or active ingredients therefore; • shaped ceramic products, e.g. clay-wares, refractories , non-oxides. Physico-chemical aspects of methods for obtaining mortars, concrete, artificial stones or ceramics , e.g. for delaying the setting time of mortar compositions. Treatment including defibrillating of materials such as fillers , agglomerated or waste materials, or refuse to enhance their filling properties in mortars, concrete or artificial stone. Porous mortars, concrete, artificial stone or ceramic ware, and the preparation thereof. Methods and apparatus for: • burning or slaking lime; • obtaining mineral binders, e.g. Portland cement or hemihydrate plaster; • the expansion of mineral fillers , such as clay, perlite or vermiculite. After- treatment of artificial stones, mortars, concrete and ceramics , e.g. coating or impregnation of green concrete after primary shaping. Non-mechanical treatment of natural stone. Processing powders of inorganic compounds in preparation to the manufacturing of ceramic products . 1 C04B (continued) CPC - C04B - 2021.08 Definition statement The joining of burned ceramics with other articles by heating. References Limiting references This place does not cover: Granulating apparatus B01J 2/00 Mechanical features relating to the working of mortars, concrete, stone, B28 clay-wares or ceramics , e.g.
    [Show full text]
  • 8 Characteristics and Properties of Silicon Carbide and Boron Carbide
    8 Characteristics and Properties of Silicon Carbide and Boron Carbide 1.0 INTRODUCTION In the previous chapter, the structure and composition of the two covalent carbides, i.e., silicon carbide and boron carbide, were reviewed. This chapter is an assessment of the properties and a summary of the fabrication processes and applications of these two compounds. Silicon carbide and boron carbide to a lesser degree are important industrial materials which are produced on a large scale in the form of powders, molded shapes, and thin films. 2.0 CHARACTERISTICS AND PROPERTIES OF SILICON CARBIDE 2.1 Historical Background and Present Status Silicon carbide was first synthesized in 1891 by Acheson by passing an electric current through a mixture of carbon powder and clay. The material was originally thought to be a mixture of carbon and corundum (aluminum oxide) and trademarked Carborundum (CARBOncoRUNDUM). 137 138 Handbook of Refractory Carbides and Nitrides Acheson soon determined that it was actually silicon carbide. The product was an immediate commercial success as an abrasive.t11t21 The Acheson process is still the major production process. In the US, over 115,000 metric tons of silicon carbide were produced in 1994 with a value estimated at $40 million, much of which was for abrasives and metallurgical uses.t31 2.2 Summary of Properties The characteristics and properties of silicon carbide are summarized in Table 8.1 t4j-t10jand reviewed in more detail in Sets. 4-8. Values quoted are for hot-pressed material and are an average of the values reported in the literature. Table 8.1: Summary of Characteristics and Properties of Silicon Carbide.
    [Show full text]
  • Structural Stability and Mechanism of Compression Of
    www.nature.com/scientificreports OPEN Structural stability and mechanism of compression of stoichiometric B13C2 up to 68GPa Received: 15 March 2017 Irina Chuvashova1,2, Elena Bykova 2,3, Maxim Bykov2, Volodymyr Svitlyk 4, Accepted: 14 July 2017 Leonid Dubrovinsky2 & Natalia Dubrovinskaia1 Published: xx xx xxxx Boron carbide is a ceramic material with unique properties widely used in numerous, including armor, applications. Its mechanical properties, mechanism of compression, and limits of stability are of both scientifc and practical value. Here, we report the behavior of the stoichiometric boron carbide B13C2 studied on single crystals up to 68 GPa. As revealed by synchrotron X-ray difraction, B13C2 maintains its crystal structure and does not undergo phase transitions. Accurate measurements of the unit cell and B12 icosahedra volumes as a function of pressure led to conclusion that they reduce similarly upon compression that is typical for covalently bonded solids. A comparison of the compressional behavior of B13C2 with that of α–B, γ–B, and B4C showed that it is determined by the types of bonding involved in the course of compression. Neither ‘molecular-like’ nor ‘inversed molecular-like’ solid behavior upon compression was detected that closes a long-standing scientifc dispute. 1 2 Boron carbide B4C was discovered in 1858, and its crystal structure was frst established in 1934. It belongs to icosahedral boron compounds, a family of crystalline solids with crystal structures based on vari- ous arrangements of B12 icosahedra, which are considered to be some kind of B12 “molecules”. In such solids chemical bonding has been rationalized in terms of polycenter bonds on the B12 closo-cluster (boron icosahe- dron) and two-electron-two-center (2e2c) and two-electron-three-center (2e3c) bonds between the clusters3.
    [Show full text]
  • Low Temperature Synthesis of Boron Carbide Using a Polymer Precursor Powder Route
    School of Metallurgy and Materials MRes in the Science and Engineering of Materials Paul Murray Low Temperature Synthesis of Boron Carbide Using a Polymer Precursor Powder Route September 2010 – September 2011 1 University of Birmingham Research Archive e-theses repository This unpublished thesis/dissertation is copyright of the author and/or third parties. The intellectual property rights of the author or third parties in respect of this work are as defined by The Copyright Designs and Patents Act 1988 or as modified by any successor legislation. Any use made of information contained in this thesis/dissertation must be in accordance with that legislation and must be properly acknowledged. Further distribution or reproduction in any format is prohibited without the permission of the copyright holder. This report is submitted in fulfilment of the requirements for the degree of MRes in the Science and Engineering of Materials. Acknowledgements The University of Birmingham Dr. Isaac Chang Dr. Lucian Falticeanu Synopsis Boron carbide has a leading role in high performance applications due to its extreme hardness, low density, high melting point, high Young’s modulus, great resistance to chemical agents, excellent thermoelastic and thermoelectric properties and high corrosion and oxidation resistance. Due to its excellent properties it has many high performance applications including; body and vehicle armour, abrasive powder, nuclear applications and aerospace applications. Currently, boron carbide is commercially produced by a carbothermal reduction process. This involves the carbon reduction of boric acid by heating in an electric heating furnace. However, the process has many associated problems, including: Considerable amount of free carbon residue in the final product.
    [Show full text]