Inscrição na biblioteca: Guest
Portal Digital Begell Biblioteca digital da Begell eBooks Diários Referências e Anais Coleções de pesquisa
High Temperature Material Processes: An International Quarterly of High-Technology Plasma Processes
SJR: 0.137 SNIP: 0.341 CiteScore™: 0.43

ISSN Imprimir: 1093-3611
ISSN On-line: 1940-4360

High Temperature Material Processes: An International Quarterly of High-Technology Plasma Processes

DOI: 10.1615/HighTempMatProc.v7.i3.90
pages 357-366

REDUCTION OF TUNGSTEN PRECURSORS IN INDUCTIVE RF DISCHARGE PLASMA REACTORS

Jan Janca
Department of Physical Electronics, Faculty of Science, Masaryk University, Kotlarska 2, CZ-611 37 Brno, Czech Republic
Marek Elias
Department of Physical Electronics, Faculty of Science, Masaryk University, Kotlarska 2, CZ-611 37 Brno, Czech Republic
Vlastimil Brozek
Institute of Chemical Technology, Technicka 5, CZ-16628 Prague; Institute of Plasma Physics, ASCR, Za Slovankou 3,182 00 Prague 8

RESUMO

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.