Numerical analysis of nitrogen-mixed argon plasma characteristics and injected particle behavior in an ICP torch for ultrafine powder synthesis
- Seoul National Univ. (Korea, Republic of). Dept. of Nuclear Engineering
The ICP (inductively coupled plasma) torches have been extensively used for the synthesis of various ceramics and new materials as effective hot-temperature heat sources in the field of material processing. Here, a numerical model is presented for the analysis of plasma characteristics of an ICP torch and gas mixing effects on the plasma when a nitrogen gas is added into the argon plasma as a carrier or sheath gas at the torch inlet. The fluid equations describing the plasma flow and temperature fields and the diffusions between two different gases are solved along with a magnetic vector potential equation for electromagnetic fields. The trajectory and the temperature change with time for a particle injected into the plasma are also investigated by a plasma-particle interaction model to find out optimum injection conditions for the synthesis of ultra/fine nitride ceramic powders. It is found from the calculations that the nitrogen-mixed argon plasma with a nitrogen carrier gas for the reaction kinetics of nitride synthesis. It is also found that the radial injection through the holes of the tube wall is preferable to the axial injection at the torch inlet for the complete evaporation of injected particle and the effective chemical reaction of reactant vapor with nitrogen. For the radial injection in an ICP torch of 20 cm in axial length, the optimum injection locations and initial velocities of 50-{micro}m aluminum particles are found for synthesizing aluminum nitride are in the range of 6{approximately}12 cm apart from the torch inlet and over 15 m/s, respectively.
- Sponsoring Organization:
- USDOE
- OSTI ID:
- 118897
- Journal Information:
- IEEE Transactions on Plasma Science, Vol. 23, Issue 4; Other Information: PBD: Aug 1995
- Country of Publication:
- United States
- Language:
- English
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