the analysis of refractory borides carbides nitrides
USAMethod of producing refractory carbides
a method of producing refractory inorganic compounds such as carbides borides nitrides silicides oxides phosphides sulphides fluorides and chlorides of metals of the iv v and vi groups in which at least one of the metals of the iv v and vi groups of the periodic system is mixed with one of the non-metals n c b si o2 p s f or cl2 and to the resulting mixture is introduced
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Metal Immiscibility Route to Synthesis of Ultrathin
the family of metal carbides nitrides and borides noted for their hardness wear resistance and high temperature stability offers much promise. 6 Here we study a unique and generic approach to synthesis of ultra-thin transition metal carbides (TMC) nitrides and borides with properties
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Metal Immiscibility Route to Synthesis of Ultrathin
Metal Immiscibility Route to Synthesis of Ultrathin Carbides Borides and Nitrides. Zixing Wang. Materials Science and Nanoengineering Rice University 6100 Main St Houston TX 77005 USA. A detailed microscopy analysis followed by density functional theory based calculation demonstrates the migration mechanism where Ta atoms prefer to
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Metal Immiscibility Route to Synthesis of Ultrathin
the family of metal carbides nitrides and borides noted for their hardness wear resistance and high temperature stability offers much promise. 6 Here we study a unique and generic approach to synthesis of ultra-thin transition metal carbides (TMC) nitrides and borides with properties
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Thermodynamic analysis for the combustion synthesis of SiC
Mar 15 1996 · Self-propagating high-temperature synthesis (SHS) or combustion synthesis (CS) has been used to produce a variety of refractory borides carbides nitrides and silicides containing ceramics and composite materials 9 .
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Processing of refractory metal borides carbides and nitrides
Transition metal borides carbides and nitrides are candidates for very high temperature applications. A review of various processing techniques to fabricate dense monolithic and composite materials is presented. In particular we focus on reactive hot pressing (RHP) which allows synthesis and densification to be achieved simultaneously. We report the RHP of composites in the Ti-B-N Zr-B-C
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Processing of refractory metal borides carbides and nitrides
Transition metal borides carbides and nitrides are candidates for very high temperature applications. A review of various processing techniques to fabricate dense monolithic and composite materials is presented. In particular we focus on reactive hot pressing (RHP) which allows synthesis and densification to be achieved simultaneously. We report the RHP of composites in the Ti-B-N Zr-B-C
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Nanomaterials based on refractory carbides nitrides and
Request PDF Nanomaterials based on refractory carbides nitrides and borides Methods for the preparation of refractory carbides nitrides and borides as ultradisperse powders nanotubes
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Development of accurate estimation methods for calculating
Factors that contribute to the heat capacities of solids are analyzed and correlation methods are developed for accurately estimating these factors for the refractory borides carbides nitrides and oxides. High temperature heat capacities calculated for the borides are found to
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Selected Problems in the Analysis of Refractory Materials
The development of refractory materials for structural and protective applications at very high temperatures has received increased emphasis in the last decade. Research on refractory compounds such as the transition metal carbides borides and nitrides has brought into focus attendant problems with analytical methods and chemical standards.
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USAMethod of producing refractory carbides
a method of producing refractory inorganic compounds such as carbides borides nitrides silicides oxides phosphides sulphides fluorides and chlorides of metals of the iv v and vi groups in which at least one of the metals of the iv v and vi groups of the periodic system is mixed with one of the non-metals n c b si o2 p s f or cl2 and to the resulting mixture is introduced
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Thermal stability of refractory materials for high
A computational thermodynamic analysis of the stability of group IV V and VI transition metal borides carbides nitrides and oxides is presented. The results of these computations can be employed to assess the stability and decomposition of these materials at high temperatures under different ambient conditions. The thermodynamic stabilities of group IV V and VI compounds increase with
Get PriceDevelopment of accurate estimation methods for calculating
Factors that contribute to the heat capacities of solids are analyzed and correlation methods are developed for accurately estimating these factors for the refractory borides carbides nitrides and oxides. High temperature heat capacities calculated for the borides are found to
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The analysis of refractory borides carbides nitrides
The analysis of refractory borides carbides nitrides and silicides / By Owen H. Kriege U.S. Atomic Energy Commission. and Los Alamos Scientific Laboratory. Abstract "Contract W-7405-ENG. 36 with the U.S. Atomic Energy Commission.""Report written March 1959. Report distributed August 27 1959."At head of title LA-2306 Chemistry--general
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USARefractory metal borides and composites
Refractory metal borides carbides nitrides and mixtures thereof of the Group IVb Vb and VIb metals are produced from a glass or microcrystalline gel formed from organo-metallic precursors. Typically TiO 2 .B 2 O 3 glass is produced by hydrolysis of titanium butoxide and trimethyl borate followed by gelling/drying. The glass may have carbon inclusions or may be mixed with carbon or aluminum
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Boridean overview ScienceDirect Topics
Refractory carbides borides and nitrides can be deposited more conveniently from volatile metal chlorides (less often fluorides) mixed with B C N source gases (boron halides hydrocarbons ammonia). Since the beginning of CVI infiltration of refractory carbides has been considered.
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(PDF) The Physics and Chemistry of carbides Nitrides and
Carbides nitrides and borides are families of related refractory materials. Traditionally they have been employed in applications associated with engineering ceramics where either high
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CHEMICAL REACTIONS OF CARBIDES NITRIDES
results under similar conditions for carbides nitrides and borides of known bonding the chemical bonding for these group IVA transition-metal refractories is discussed with reference to the theories described by Engel (ref. 1) and Samsonov (ref. 2). diborides of titanium (Ti) and zirconium (Zr). In general three aqueous systems
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Electrical properties of high-temperature oxides borides
High-temperature materials including oxides borides carbides and nitrides encompass all types of conductors metallic semiconducting and ionic. Their electrical conductivities are generally very sensitive to impurities regardless of the type of conductor. For large band-gap materials which includes most of the oxides the conductivities at low temperatures are frequently dominated by
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Comprehensive Hard MaterialsGoogle Books
Feb 01 2014 · Comprehensive Hard Materials deals with the production uses and properties of the carbides nitrides and borides of these metals and those of titanium as well as tools of ceramics the superhard boron nitrides and diamond and related compounds. Articles include the technologies of powder production (including their precursor materials) milling granulation cold and hot compaction
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Nanomaterials based on refractory carbides nitrides and
Request PDF Nanomaterials based on refractory carbides nitrides and borides Methods for the preparation of refractory carbides nitrides and borides as ultradisperse powders nanotubes
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Intro to Transition Metal Carbidesropine
Most of the Group IV-V metal carbides conform to the Hägg rules which were developed empirically to "predict" the structures of the transition metal borides carbides halides and nitrides. 22 The structure adopted by the metal carbide is determined by the ratio of the radius of the nonmetal atom (r x) to that of the metal atom (r m).
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Processing of refractory metal borides carbides and nitrides
Transition metal borides carbides and nitrides are candidates for very high temperature applications. A review of various processing techniques to fabricate dense monolithic and composite materials is presented. In particular we focus on reactive hot pressing (RHP) which allows synthesis and densification to be achieved simultaneously.
Get PriceLanthanides Boride Carbide and Nitride Compounds
The rare earth borides carbides and nitrides tend to be highly refractory compounds typically with melting points above 2300 K. One way of looking at the less metal-rich compounds is that the boron carbon and nitrogen atoms respectively form strongly covalent atomic networks in which rare earth atoms occupy particular spaces/voids.
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Handbook of refractory carbides and nitrides Properties
OSTI.GOV Book Handbook of refractory carbides and nitrides Properties characteristics processing and applications THE ANALYSIS OF REFRACTORY BORIDES CARBIDES NITRIDES AND SILICIDES. Technical Report Kriege O H. Methods are presented for the analysis of 41 refractory materials. An evaluation of the accuracy and the precision of these
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The wetting of refractory carbides borides and nitrides
The investigation has shown that the wetting of refractory compounds by metals is directly linked with the character of their chemical reaction as well as with the direction of preferential transport of elements from the melt to the refractory support or vice versa. The wetting of a support material by a melt can be controlled by means of additions to one of the contacting materials which
Get Price-1- THSBMAL DECOMPOSITION OF REFRACTORY BORIDES
elements are the oxides nitrides carbides borides silicides and phosphides. Some important compounds of titanium zirconium and hafnium are listed below. BO HIDES (TiB) TiB2 CARBIDES TiC. 1.0-0 ZrB ZrB HfB ZrC 12 SILICIDES NITRIDES OXIDES TiN TiO Ti0„ Zr°2 ZrN HfN PHOSPHIDES Hf02 Ti Si Zr-Si HfpSi Ti Si- Zr Si Hf Sin 5 3 2 3 2 TiSi
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USAPreparation and sintering of refractory metal
The invention relates to the production of desirably consolidated high purity refractory metal borides carbides nitrides or mixtures combinations of cermets thereof. In the preparation a second stage reaction is conducted at reduced pressure and sintering temperature. Furthermore it is carried out in the presence of sintering aid which can be initially present as a particulate material
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Transition metal borides carbides and nitrides are candidates for very high temperature applications. A review of various processing techniques to fabricate dense monolithic and composite materials is presented. In particular we focus on reactive hot pressing (RHP) which allows synthesis and densification to be achieved simultaneously. We report the RHP of composites in the Ti-B-N Zr-B-C
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