Modelling of the in-flight synthesis of TaC nanoparticles from liquid precursor in thermal plasma jet

Vorobev, Anatoliy; Zikanov, Oleg; Mohanty, Prasanna

doi:10.1088/0022-3727/41/8/085302

Cited by 13 publications

(6 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Therefore, the synthesis of fine tantalum carbide powders is of interest. Methodologies for the synthesis of this material include carbothermal reduction and subsequent carburization, impulse plasma synthesis in a liquid, gas‐phase condensation, solvothermal synthesis, mechano‐chemical synthesis, alkalide reduction, organometallic reactions, metathesis reactions, solid‐state reactions, synthesis in ionic/electronic melts, and electrosynthesis 9–21 . Variations of these techniques include the use of elements, compounds, or polymeric precursors as raw materials and the use of microwaves or electric fields to promote the reaction.…”

Section: Introductionmentioning

confidence: 99%

“…Methodologies for the synthesis of this material include carbothermal reduction and subsequent carburization, impulse plasma synthesis in a liquid, gas-phase condensation, solvothermal synthesis, mechanochemical synthesis, alkalide reduction, organometallic reactions, metathesis reactions, solid-state reactions, synthesis in ionic/ electronic melts, and electrosynthesis. [9][10][11][12][13][14][15][16][17][18][19][20][21] Variations of these techniques include the use of elements, compounds, or poly-meric precursors as raw materials and the use of microwaves or electric fields to promote the reaction. These techniques have at least one of a few shortcomings, including the inability to produce nanostructured tantalum carbide, high-energy input, long processing times, and/or issues with reaction scalability.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Statistical Experimental Design Approach for the Solvothermal Synthesis of Nanostructured Tantalum Carbide Powders

Kelly

Graeve

2011

Journal of the American Ceramic Society

View full text Add to dashboard Cite

We report on the preparation of tantalum carbide nanopowders via a modified solvothermal synthesis route by using experimental design principles. The reaction proceeds by self‐propagating behavior in a molten metal after thermal‐ignition of tantalum chloride, carbon, and a metal reductant. A 4 × 4 × 3 experimental design matrix was performed, without replication, to observe the effects of carbon stoichiometry, reductant stoichiometry, and reductant type on process response variables concerning phase purity, compound stoichiometry, crystallite size, particle size, and surface characteristics. Statistical verifications of the observed effects were performed using a 2 × 2 × 2 experimental design matrix with replication. Eleven conditions resulted in phase‐pure tantalum carbide, with an additional four nonoxide conditions with low secondary‐phase content. The stoichiometry (x in TaCx) ranged from 0.92 to 0.96, the average crystallite size ranged from 24 to 68 nm, the specific surface area ranged from 25 to 66 m2/g, and the average particle size ranged from 93 to 123 nm, indicating a low level of agglomeration.

show abstract

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Statistical Experimental Design Approach for the Solvothermal Synthesis of Nanostructured Tantalum Carbide Powders

Kelly

Graeve

2011

Journal of the American Ceramic Society

View full text Add to dashboard Cite

show abstract

“…Particularly, models based on aerosol dynamics have been used to study nanopowder production using several types of thermal plasmas, as described in an earlier review article [12]. By virtue of the efforts of several groups, the spatial distributions of nanopowder around plasmas or in downstream chambers have been clarified while taking account of both growth and transport under various conditions [22][23][24][25][26][27][28][29][30][31][32][33]. However, all those simulations were restricted in the steady fields of the nanopowder as well as the plasma flow.…”

Section: Thermal Plasma For Nanopowder Productionmentioning

confidence: 99%

Modeling and simulation of a turbulent‐like thermal plasma jet for nanopowder production

Shigeta

2018

IEEJ Transactions Elec Engng

View full text Add to dashboard Cite

This paper discusses theoretical models and numerical methods to simulate turbulent thermal plasma flow transporting a nanopowder. In addition to a thermal plasma flow model, a sophisticated model is described mathematically for the nanopowder's collective growth by homogeneous nucleation, heterogeneous condensation, and coagulation among nanoparticles, and also transport by convection, diffusion, and thermophoresis, simultaneously. Demonstrative simulations show clearly that a suitable numerical method with high‐order accuracy should be used for long and robust simulation capturing multiscale eddies and steep gradients of temperature, which are the turbulent features of thermal plasma flows with locally variable density, transport properties and Mach numbers. Eddies are first generated at the interfacial region between the plasma jet and ambient nonionized gas by fluid‐dynamic instability. As a result of the eddies' generation–breakup process, the plasma flow entrains the ambient cold gas and deforms its shape traveling downstream. Numerous sub‐nanometer particles are generated by nucleation and condensation in the thin layers near the plasma jet. Those particles diffuse and increase their size, thus decreasing their number by coagulation. Cross‐correlation analysis suggests that the nanopowder distribution distant from a plasma jet can be controlled by controlling the temperature fluctuation at the upstream plasma fringe. © 2018 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.

show abstract

“…Particularly, mathematically described models based on aerosol dynamics have been adopted to elucidate nanopowder fabrication using thermal plasmas of several types [13]. Because of the efforts of several groups, the spatial distributions of nanopowder around plasmas or in downstream chambers have been revealed while considering both growth and transport in various conditions [27][28][29][30][31][32][33][34][35][36][37][38]. However, all of those simulations were restricted in steady fields of the nanopowder as well as the plasma flow.…”

Section: Introductionmentioning

confidence: 99%

Simulating Turbulent Thermal Plasma Flows for Nanopowder Fabrication

Shigeta

2020

Plasma Chem Plasma Process

View full text Add to dashboard Cite

This article presents descriptions of theoretical models and numerical methods for simulating turbulent thermal plasma flow with nanopowder growth. Turbulence models must express turbulent and laminar states because both states co-exist with thermal plasmas showing large density variation and transport properties. Time-dependent 3D simulations are conducted based on Large Eddy Simulation using a dynamic Smagorinsky model. Results show significant difference depending on temporal and spatial discretization schemes and velocity-pressure coupling algorithms. Simulation results demonstrate that advanced numerical methods with high-order accuracy should be used for long and robust computations capturing steep gradients of nanopowder concentration and plasma temperature and 3D dynamic motions of multiscale vortices, which are turbulent features of thermal plasma flows with low Mach numbers. A thermal plasma jet generates a doublelayer structure of inner high-temperature thick vortex rings and outer low-temperature thin vortex rings near the nozzle exit. Flowing downstream, these vortices interact, deform, and break up. Consequently, plasma transits to a complex thermal flow. The widely spreading distribution of multiscale vortices agrees with experimental observations, which are not simulated using conventional methods. Nanopowder is generated from material vapour by nucleation and condensation at interfacial regions between plasma and cold gas. Those regions include numerous vortices. Therefore, the vortices convey the nanopowder, producing a complex distribution of nanopowder. Simultaneously, the nanopowder diffuses and increases in size, decreasing in number by interparticle coagulation. Cross-correlation analysis suggests that a nanopowder distribution distant from a plasma jet can be controlled through temperature fluctuation control at the upstream plasma fringe.

show abstract

Modelling of the in-flight synthesis of TaC nanoparticles from liquid precursor in thermal plasma jet

Cited by 13 publications

References 22 publications

Statistical Experimental Design Approach for the Solvothermal Synthesis of Nanostructured Tantalum Carbide Powders

Statistical Experimental Design Approach for the Solvothermal Synthesis of Nanostructured Tantalum Carbide Powders

Modeling and simulation of a turbulent‐like thermal plasma jet for nanopowder production

Simulating Turbulent Thermal Plasma Flows for Nanopowder Fabrication

Contact Info

Product

Resources

About