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Plasma Chemistry and Plasma Processing

, Volume 17, Issue 3, pp 353–370 | Cite as

Heat transfer in RF plasma sintering: Modeling and experiments

  • N. P. Tandian
  • E. Pfender
Article

Abstract

The mechanisms of heat transfer from an argon RF plasma, generated in a water-cooled quartz tube, to a sintering sample immersed into the plasma and to the walls of the plasma torch have been studied both analytically and experimentally for pressures from 1 to 50 torr. The model, based on the assumption of chemical equilibrium in a two-temperature plasma with rotational symmetry, includes the influence of the magnetic field and of the Knudsen number on the thermal conductivity of the plasma. At pressures below 20 torr heat transfer to the sintering sample is enhanced compared to heat transfer to the wall of the plasma torch. This nonsymmetry is attributed to the Hall parameter and Knudsen number effect. The relative importance of the two effects is a function of the pressure. A comparison with experiments, based on calorimetric and indirect heat transfer measurements for a range of pressures and power levels, indicates satisfactory agreement with analytical predictions, with the exception of larger discrepancies at higher power levels and relatively low pressures. For pressures below 5 torr, the chemical equilibrium assumption becomes questionable, i.e., the sintering model underestimates the heat transfer to the sintering sample.

Key Words

RF plasma sintering reduced pressures effect on heat transfer Hall and Knudsen number effect 

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Copyright information

© Plenum Publishing Corporation 1997

Authors and Affiliations

  • N. P. Tandian
    • 1
  • E. Pfender
    • 1
  1. 1.Department of Mechanical Engineering and ERC for Plasma-Aided ManufacturingUniversity of MinnesotaMinneapolis

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