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ISSN Druckformat: 1093-3611
ISSN Online: 1940-4360
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REDUCTION OF TUNGSTEN PRECURSORS IN INDUCTIVE RF DISCHARGE PLASMA REACTORS
ABSTRAKT
The new plasma chemical reduction techniques of tungsten precursors were investigated with the aim of producing tungsten powder with high sinterable activity, permitting to rise the density of tungsten compact products above the hitherto technological limit. The application of non-isothermic hydrogen plasma allows the iniciation of reduction processes at low temperature of neutral gas. The high electron temperature makes possible the increase in atomic hydrogen concentration entering the reduction process. For the reduction of pulverised ammonium paratungstate (APT) to tungsten metal powder by hydrogen plasma we used hydrogen as the main gas, in some cases admixture of argon was applied. The series of experiments with APT of different granulometry demonstrated that reduction takes place even at 600 °C and that the kinetics of the reaction is mainly influenced by diffusion of hydrogen into solid phase pores.