Thermal conductivities, electrical resistivities, and thermal expansion of titanium carbonitrides and oxycarbides

Иванов, Н. А.; Andreeva, L. P.; Gel’d, P. V.

doi:10.1007/bf00797336

Cited by 9 publications

(5 citation statements)

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“…Such low values can be related to the presence of O in TiC as a solid solution of TiO in TiC, giving an oxycarbide phase . Similar values of a have already been reported and attributed to an oxycarbide phase Ti 2 OC ( a = 4.2960 Å) . The low mass loss m L value recorded (cf.…”

Section: Resultssupporting

confidence: 81%

“…29 Similar values of a have already been reported and attributed to an oxycarbide phase Ti 2 OC (a ) 4.2960 Å). 30 The low mass loss m L value recorded (cf. Table 2) after the T a ) 1200 °C annealing treatment (m L ) 29.7 ( 1.0 wt %) confirms, when compared to m L ) 48.3 wt % given by eq 1, that the carburization was not complete and thus allowed some unreduced O in the powder.…”

Section: (B) Tic Nanopowder Formation After Carburization Let Us Firs...mentioning

confidence: 97%

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TiC Nanocrystal Formation from Carburization of Laser-Grown Ti/O/C Nanopowders for Nanostructured Ceramics

et al. 2005

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Refractory carbide ceramics (TiC and ZrC) raise interest as promising materials for high-temperature applications such as structural materials for the future generation of nuclear reactors. In this context, nanostructured ceramics are expected to exhibit improved thermomechanical properties as well as better behavior under irradiation when compared to conventional materials. It is therefore necessary to synthesize carbide nanocrystals of such materials to elaborate the ceramics. We report here the formation study of TiC nanocrystals through the direct carburization of Ti/O/C nanopowders grown by laser pyrolysis. A spray of titanium tetraisopropoxide was laser pyrolyzed with ethylene as the sensitizer, leading to Ti/O/C nanopowders with various C contents controlled by the synthesis conditions. Annealing treatments performed on these nanopowders under an inert atmosphere without any C addition enabled the formation of TiC grains through the carburization of the oxide phase by free C incorporated during the synthesis. The powders were characterized by X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. The final TiC grain size was about 80 nm, and the grains were monocrystalline. The influence of the free C content on the grain growth during the annealing step, together with its effects on the densification of the ceramics after sintering by high-pressure flash sintering, was examined. A 93% densification was finally achieved.

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Section: Resultssupporting

confidence: 81%

Section: (B) Tic Nanopowder Formation After Carburization Let Us Firs...mentioning

confidence: 97%

TiC Nanocrystal Formation from Carburization of Laser-Grown Ti/O/C Nanopowders for Nanostructured Ceramics

et al. 2005

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“…30 A previous study by Ivanov et al has shown that conductivities are reduced at low carbon contents due to the increased level of defects and the greater ionic character of the bonding. 13 Determination of the variation of conductivity with composition is complicated by the difficulty in obtaining defect-free high density samples from these materials. For compounds where x=0.2 and greater there appears to be a decrease in resistivity as carbon content increases, however the effects of density and microstructure cannot be discounted.…”

Section: Resultsmentioning

confidence: 99%

“…Studies on titanium oxycarbide thin films have shown that the optical, mechanical and electrocatalytic properties can be tailored by altering the processing conditions. 13 Titanium oxycarbide nanotubes and thin films have been utilised as electrically conductive substrates for electrocatalysts. 14,15 The high hardness of titanium oxycarbide makes it suitable for use in wear resistant coatings.…”

Section: Introductionmentioning

confidence: 99%

Studies on the crystal structure, magnetic and conductivity properties of titanium oxycarbide solid solution (TiO_1−xC_x)

et al. 2016

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Titanium oxides and carbides are often considered as electrode materials in energy conversion and storage devices due to their high potential conductivity and good stability. Titanium monoxide and titanium carbide have structures that can both be described as rocksalt with the same cubic close packed titanium sublattice with oxygen and carbon respectively occupying the octahedral interstices; however the oxide is characterised by extensive defects on both sublattices whilst the carbide is stoichiometric and might be considered as an interstitial metal. Despite the anticipated very different natures of the oxide and carbide sublattices, these two phases actually form a complete solid solution. In the present investigation, we carefully characterise this titanium oxycarbide solid solution, reporting on crystal structure, magnetic and electronic conduction properties. Titanium oxycarbide powders (TiO1-xCx with x = 0 ≤ x ≤ 1) have been prepared by solid state reaction of TiO and TiC powder under controlled environments at elevated temperatures. X-ray diffraction and pycnometric density measurements illustrate the gradual transition of crystal structure of titanium oxycarbides from vacancy containing rock-salt structure of TiO to the fully occupied TiC with increase in carbon content in the oxycarbide lattice. The variation of lattice parameter of oxycarbide crystal as a function of carbon content has been found to be non-linear which can be attributed to variations in the level of vacancies present in metal as well as non-metal sub-lattices.The existence of short-range ordering of anion vacancies in oxycarbide with a nominal composition of TiO0.5C0.5 where half of oxygen of TiO is replaced by carbon has been confirmed by selected-area electron diffraction studies. Low temperature magnetic and conductivity measurements confirm that all oxycarbide compositions are Pauli paramagnetic and good metallic conductors.

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“…Titanium oxycarbide (TiC x O y ), which possesses excellent electrical and thermal conductivity, extremely high hardness and high melting point, chemical and thermal stability etc, 1 has been widely applied in surface decorative fields. [2][3][4][5][6] More recently, a novel electrowinning process of titanium using a consumable TiC x O y anode was reported, [7][8][9][10] in which production of cost-affordable TiC x O y with determined carbon and oxygen content is crucial.…”

mentioning

confidence: 99%

Electrosynthesis of Ti₂CO_nfrom TiO₂/C Composite in Molten CaCl₂: Effect of Electrolysis Voltage and Duration

Tang

Xiao

Tian

et al. 2013

J. Electrochem. Soc.

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Ti2COn powders with controllable oxygen contents have been successfully synthesized by electro-reduction of solid TiO2-graphite composite precursors in molten CaCl2. The effect of electrolysis time and applied cell voltage on the carbon and oxygen content of the product was systematically investigated. The reduction pathway of the composite electrode was studied based on the analysis of intermediate products using X-ray diffraction (XRD), scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). It is suggested that the reduction starts with converting TiO2 and graphite to CaTiO3 and Ti2COn. The resulting CaTiO3 is then reduced to CaTi2O4 which is subsequently reduced to Ti2COn. The present graphite significantly accelerates the electro-reduction of TiO2. The oxygen content decreases with increasing the electrolysis cell voltage and prolonging the electrolysis time. It is found that the cell voltage and electrolysis duration should be strictly controlled to avoid oxygen-depletion in the final product. The obtained product shows good electronic conductivity at room temperature. This process exhibits a relatively high current efficiency for production of Ti2COn from TiO2-graphite composite.

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Thermal conductivities, electrical resistivities, and thermal expansion of titanium carbonitrides and oxycarbides

Cited by 9 publications

References 1 publication

TiC Nanocrystal Formation from Carburization of Laser-Grown Ti/O/C Nanopowders for Nanostructured Ceramics

TiC Nanocrystal Formation from Carburization of Laser-Grown Ti/O/C Nanopowders for Nanostructured Ceramics

Studies on the crystal structure, magnetic and conductivity properties of titanium oxycarbide solid solution (TiO_1−xC_x)

Electrosynthesis of Ti₂CO_nfrom TiO₂/C Composite in Molten CaCl₂: Effect of Electrolysis Voltage and Duration

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Thermal conductivities, electrical resistivities, and thermal expansion of titanium carbonitrides and oxycarbides

Cited by 9 publications

References 1 publication

TiC Nanocrystal Formation from Carburization of Laser-Grown Ti/O/C Nanopowders for Nanostructured Ceramics

TiC Nanocrystal Formation from Carburization of Laser-Grown Ti/O/C Nanopowders for Nanostructured Ceramics

Studies on the crystal structure, magnetic and conductivity properties of titanium oxycarbide solid solution (TiO1−xCx)

Electrosynthesis of Ti2COnfrom TiO2/C Composite in Molten CaCl2: Effect of Electrolysis Voltage and Duration

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Studies on the crystal structure, magnetic and conductivity properties of titanium oxycarbide solid solution (TiO_1−xC_x)

Electrosynthesis of Ti₂CO_nfrom TiO₂/C Composite in Molten CaCl₂: Effect of Electrolysis Voltage and Duration