Titanium Carbide Nanopowders Research Articles

Структура и прочность пористых материалов на основе порошков карбида титана разной дисперсности

Materials with porosity from 67.5 to 82.5 % were obtained from mixtures of titanium carbide powders and ammonium bicarbonate blowing agent by sintering in vacuum at temperatures of 1300 – 1500 °C. X-ray phase analysis of porous materials found that the crystal lattice parameter decreases with increasing sintering temperature. This indicates a decrease in the content of bound carbon C/Ti in titanium carbide. As a result of a comparative study of the obtained according to bending test strength characteristics of materials synthesized from nano- and submicron titanium carbide powders, it was found that the strength have close values. Ultimate bending strength are in the range of 2.6 – 18.1 MPa. As the porosity of the material increases, the tensile strength decreases. Fracture is brittle. In the fracture of materials obtained from titanium carbide nanopowder, destruction is observed both along the body and along the grain boundaries regardless of the sintering temperature. In materials obtained by sintering submicron titanium carbide powder at 1500 °C, the destruction occurs predominantly along the body of the grains. It has been found that under the same sintering conditions, the density of the porous material made of titanium carbide nanopowder is higher than that of the material made of submicron powder.

Synthesis and characterization of mesoporous TiC nanopowder/nanowhisker with low residual carbon processed by sol–gel method

In the present research, Titanium carbide nanopowders and nanowhiskers were synthesized by the sol-gel process using phenolic resin and titanium alkoxide as precursors. The synthesis process was performed in a quaternary alkoxide-catalyst-dispersant-water system. The effect of synthesis temperature and soaking time on the free carbon content and the formation and morphology of TiC nanopowders was investigated. It was revealed that titanium carbide began to nucleate at a temperature of approximately 1200 °C. This process ended at 1400 °C. Surface studies demonstrated that the pores on the surface of the synthesized nanopowders were in the meso range and had a specific surface area of 150 m2/g. Microstructural images indicated that over time, TiC nanowhiskers heterogeneously nucleated from the particle surface and grew in a soaking time of 3 h. The free carbon content detected in the synthesized product under a soaking time of 3 h was reported to be less than 1%.

Precursor Selection for Sol–Gel Synthesis of Titanium Carbide Nanopowders by a New Hesitant CUBIC Fuzzy Multi-Attribute Group Decision-Making Model

In this paper, we define hesitant cubic TOPSIs method. We develop the numerical application and different method. We define the new idea of Hesitant Cubic Gray Analysis Set. We proposed the HCF-MAGDM model and relationships among hesitant cubic TOPSIS method with hesitant cubic gray relation analysis method being introduced. Finally, using the proposed method to Sol–Gel synthesis of titanium carbide (TiC) nanopowders for selection, we analyzed the proposed method by using a numerical application to Sol–Gel synthesis of TiC nanopowders.

Influence of deep cryogenic treatment on viscous behavior of TiC nanopowder/water nanofluid

This paper presents the influence of cryogenic treatment on viscosity of Titanium carbide (TiC)/Water nanofluid. Deep cryogenic treatment is a cooling treatment at −196 °C for 24 h, which is applied to TiC nanopowder. The viscosity is measured for both the TiC/water nano fluid and deep cryogenically treated TiC/water nanofluid. The deep cryogenically treated TiC / Water nano fluid viscosity shows low viscosity when compared to conventional TiC/water nano fluid. The homogenous distribution of TiC nanopowder is responsible for decreasing the viscosity. However, no significant changes are observed in the crystallite size of TiC and Cryo-TiC nano powder from XRD analysis. Scanning Electron Microscope analysis is also done on TiC nano powder and Cryo-TiC nano powder. The homogenous distribution of TiC nano powder is shown in the analysis due to deep cryogenic treatment.

Precursor Selection for Sol–Gel Synthesis of Titanium Carbide Nanopowders by a New Cubic Fuzzy Multi-Attribute Group Decision-Making Model

Abstract In this paper, we construct an extended version of the TOPSIS method by using cubic information, and provide a numerical application to verify and demonstrate the practicality of the method. A new extension of the gray relation analysis (GRA) method is introduced by using cubic information. We also propose the cubic fuzzy multi-attribute group decision-making model, and the relation between the cubic TOPSIS method and the cubic gray relation analysis (CGRA) method is introduced. Finally, the proposed method is used for selection in sol–gel synthesis of titanium carbide nanopowders. We analyzed the proposed method by using a numerical application to sol–gel synthesis of titanium carbide nanopowders.

USE OF DOUBLE VOIGT METHOD IN X-RAY DIFFRACTION STUDY OF THE MICROSTRUCTURE OF THE TITANIUM CARBIDE NANOPOWDERS PRODUCED BY PLASMA-CHEMICAL SYNTHESIS

The size of the regions of coherent scattering and microstrain are determined using «double-Voigt» method and XRD data (integral breadth of 8 diffraction) for titanium carbide nanopowders obtained by plasmachemical synthesis. The results are compared with similar characteristics calculated by Williamson – Hall method. The coherently scattering domain size ranges within 12 – 180 nm. The size of coherent scattering domain determined by x-ray diffraction method for titanium carbide powder is close to the particle size calculated by the BET method. The Double Voigt method is advantageous for boundary (both for small and large) values of the size of titanium carbide particles. The broadening of x-ray diffraction peaks is attributed mainly to the small size of coherently scattering domains. The rms microstrain values are negligible (0.0001 – 0.0004).

Tuning Surface Chemistry of TiC Electrodes for Lithium–Air Batteries

One of the key problems hindering practical implementation of lithium–air batteries is caused by carbon cathode chemical instability leading to low energy efficiency and short cycle life. Titanium carbide (TiC) nanopowders are considered as an alternative cathode material; however, they are intrinsically reactive toward oxygen, and its stability is controlled totally by a surface overlayers. Using photoemission spectroscopy, we show that lithium–air battery discharge product, lithium peroxide (Li2O2), easily oxidizes clean TiC surface. At the same time, TiC surface, which was treated by molecular oxygen under ambient conditions, shows much better stability in contact with Li2O2 that can be explained by the presence of a surface layer containing a significant amount of elemental carbon in addition to oxides and oxycarbides. Nevertheless, such protective coatings produced by room temperature oxidation are not practically useful as one of its components, elemental carbon, is oxidized in the presence of lithi...

A study on the production of titanium carbide nano-powder in the nanostate and its properties

The plasma synthesis of titanium carbide nano-powder in the conditions close to industrial was studied. Titanium carbide TiC is a wear- and corrosion-resistant, hard, chemically inert material, demanded in various fields for the production of hard alloys, metal- ceramic tools, heat-resistant products, protective metal coatings. New perspectives for application titanium carbide in the nanostate can be found in the field of alloys modification with different composition and destination.

A novel sonochemical synthesis of nano-size silicon nitride and titanium carbide

Nano-size ceramic powders of silicon nitride and titanium carbide have been successfully synthesized by a novel sonochemical method in a greener, faster, facile, and safer way. This simplest method to obtain silicon nitride nanopowder involves reacting silicon dioxide with activated carbon in liquid ammonia for one hour using ultrasound energy at 20kHz. Titanium carbide nano-powders have been successfully synthesized by reacting titanium dioxide with activated carbon in the ratio 1:3. The product was characterized by Scanning electron microscopy (SEM), X-ray powder diffraction (XRD) to know the phase composition, Size distribution analysis by intensity using zeta sizer showed that the samples consisted of particles with an average diameter of 76nm for Silicon nitride and 127nm for Titanium carbide respectively. Si3N4 and TiC nanopowders were obtained with the specific surface area of 803.67m2/g and 731.78m2/g respectively.

Concentration and state of light elements in titanium carbide nanopowders

We have studied the effect of process parameters (temperature) in the reduction of titanium oxide with calcium hydride and calcium carbide on the concentrations and state of light elements (H, O, N, C, and S) in the reaction product and identified the oxygen-containing phases present in the titanium carbide (TiC) nanopowders obtained by reducing TiO2 with calcium hydride and calcium carbide. The oxygen present in the powders can be divided qualitatively and quantitatively into oxygen in adsorbed water, oxygen in organic compounds on the surface, and oxygen in the oxide layer on the surface of the carbide nanoparticle. We have performed fractional gas analysis for carbon in the titanium carbide nanopowders and assessed the effect of synthesis temperature on the average particle size and oxygen content of the nanopowders.

Fabrication of titanium carbide nano-powders by a very high speed planetary ball milling with a help of process control agents

Nano-sized TiC ceramic powders were fabricated by very high speed planetary ball milling, especially using coarse (micron-sized) starting powders with the help of process control agents, and their refinement behavior was investigated as a function of the milling time and ball size. Fine and uniform TiC nano-particles were achieved through a short-time mechanical milling for 60min, in which small-sized milling balls were fairly advantageous to homogeneous particle refinement by inducing low-energy, but high-frequency collisions. Moreover, a liquid-type process control agent such as toluene played a crucial role in refining the TiC nano-particles, owing to its superior capability for heat dissipation during the milling process. Under the estimated optimal milling conditions, it is notable that the particle size of the TiC powders was effectively reduced well below 50nm, which was reliably characterized by direct transmission electron microscopy along with a complementary acoustic particle size analysis.

Self-propagating high-temperature synthesis of titanium carbide nanopowder from granulated batch

The parameters and products of combustion of porous granulated batch consisting of Ti + C + cellulose nitrate with addition of KCl, NaCl or K 2 CO 3 salts or/and С 6 Н 8 Cl 14 perchlorinated resin have been investigated allowing for evolved impurity gas filtration. The effect of these components is shown and structured titanium carbide powder formation conditions are found.

Self-propagating high-temperature synthesis of titanium carbide nanopowder from the granulated charge

Parameters and combustion products of the Ti + C + cellulose nitrate porous granulated batch with added KCl, NaCl, or K2CO3 salts and/or C6H8Cl14 perchlorovinyl resin allowing for the evolved impurity gas filtration are investigated. The influence of these additives is shown and the formation conditions of nanostructured titanium carbide powder are found.

Using a cobalt activator to synthesize titanium carbide (TiC) nanopowders

Titanium carbide (TiC) nanopowders were successfully synthesized by in-situ reduction and carbonization using a precursor comprising elemental titanium, carbon, and cobalt. The samples prepared at different conditions were characterized by X-ray diffraction and transmission electron microscopy techniques. The thermolysis process of the precursor was investigated by themogravimetric analysis and differential thermal analysis. The experimental results show that the samples have average sizes ranging within 30–40nm. In addition, the experimental temperature is 100–900°C lower and the reaction time is 2–90h shorter than those used in the conventional carbothermal reduction method.

Precursor Selection for Sol‐Gel Synthesis of Titanium Carbide Nanopowders by a New Intuitionistic Fuzzy Multi‐Attribute Group Decision‐Making Model

This article develops a new intuitionistic fuzzy multi‐attribute group decision‐making model to solve precursor selection problems. The proposed model is based on a hybridization of intuitionistic fuzzy sets theory, grey relational analysis and technique for order performance by similarity to ideal solution method. To better describe the uncertain decision environment, multi‐attribute group decision‐making method with completely unknown weights of both experts and attributes is proposed in an intuitionistic fuzzy setting. Finally, the selection of the carbon source in synthesis of nanocrystalline titanium carbide powders by sol‐gel route as an application example is solved by the proposed model, and the implementation of the model is illustrated completely.

Synthesis and Characterization of Nanosized Titanium Carbide by Carbothermal Reduction of Precursor Gels

Investigations have been made on obtaining of nanosized powders of titanium carbide (TiC) by carbothermal reduction of a precursor prepared by sol-gel process. Two methods of precursor gels fabrication of TiC were used: Ti (IV) chloride, ethyleneglycol and citric acid (series A) and Ti (IV) n-propoxide, saccharose and acetic acid (series B ). The resulting xerogels are calcined under flowing argon at different temperatures ranging from 800 °C to 1400 °C with holding time from 0.5 h to 10 h. TiC nanopowders were obtained with the specific surface area of 30 m 2 /g – 200 m 2 /g and the size of TiC crystallites of 40 nm – 45 nm. Only the TiC phase has been found by the XRD analysis, but the presence of also some oxygen and free carbon depending on synthesis conditions has been found by chemical analysis. For compacting investigations with spark plasma sintering (SPS) method (1800 °C, heating rate of 100 °C /min and dwelling time of 5 min.) TiC nanopowder (SSA of 88 m 2 /g, containing 72.7 wt. % Ti, 6.6 wt. % O, 20.5 wt. % C total and 7.2 wt. % C free ) was used. The sintering begins at 1150 °C, but change of density ends at 1650 °C. The density at this temperature reaches only 89 % of the theoretical and does not rise until 1800 °C. This is probably due to the presence of free carbon in investigated sample, retarding sintering. A significant decrease of admixtures has been observed in ceramic material during sintering. DOI: http://dx.doi.org/10.5755/j01.ms.18.1.1346

Low temperature synthesis of visible light responsive rutile TiO2 nanorods from TiC precursor

A nano-structured TiO2 with rutile phase was synthesized by using the hydrothermal method from a titanium carbide (TiC) nano-powder precursor at low temperature to produce a stable visible light responsive photocatalyst. The rutile phase was formed at temperature as low as 100°C, and both synthesis time and temperature affected its formation. The rutile particles showed a faceted nano-rod structure, and were tested for absorption and photo-degradation ability under visible light. Particles with shorter synthesis times showed higher visible light absorption and corresponding photo-degradation ability, while those synthesized at lower temperatures had lower, but still evident, degradation ability under visible light.

Synthesis of titanium carbide nanopowders and production of porous materials on their basis

A technology for the synthesis of titanium carbide nanopowders with a narrow particle-size distribution and a small concentration of impurities has been developed. Conditions for pressing and sintering titanium carbide powders, which served as a basis for the creation of a porous material with an open porosity of up to 50%, have been determined. The ultimate bending strength of the porous material tended to decrease as the sintering temperature increased from 1250 to 1550°C, but it was still in the range of 66 to 95 MPa.

Preparation of mesophase pitch doped with TiO 2 or TiC particles

The co-pyrolysis of a petroleum residue with two different sources of titanium (tetrabutyl-ortotitanate (TBO) or titanium carbide nano-powder) was carried out to obtain mesophase pitches containing TiO 2 or TiC nanoparticles. Co-pyrolysis is an appropriate technique to achieve a good dispersion and low particle size. In the case of TBO, TiO 2 nanoparticles (5–20 nm) are observed, which are forming aggregates, the largest of them being 1–2 μm. In the case of TiC nano-particles, they are more difficult to disperse and larger aggregates are formed, although the final material is rather homogenous. The chemistry of pyrolysis for the production of doped and undoped mesophase pitches has been followed by means of solvent insolubility, XRD, XPS, FTIR and elemental analysis. They show evidences of promotion of the formation of mesophase in the presence of the titanium-containing particles, especially in the presence of TiO 2. The final materials can be of great value as precursors to produce high density titanium doped graphites for nuclear and space applications.

Synthesis of titanium carbide nano-powders by thermal plasma

Abstract The paper presents a thermodynamic analysis for predicting the conditions for the plasma synthesis of TiC powders. The paper also investigates the effects of feeding rate and molar ratio. The experimental results show that TiC powders are synthesized by thermal plasma and the average size of the TiC powders is less than 100 nm.