On the reduction of NS-doped tungsten blue oxide—Part I: Literature review

• Published in: International journal of refractory metals & hard materials 1991, Vol.10 (2), p.83-90
• Main Authors: Zeiler, B., Schubert, W.D., Lux, B.
• Format: Article
• Language: English
• ISSN: 0263-4368; 2213-3917
• DOI: 10.1016/0263-4368(91)90026-K

This paper reviews literature on the K, Al, Si-doping of tungsten blue oxides and the subsequent hydrogen reduction to tungsten metal powder. Some unique properties of the blue oxide with respect to the reactions during doping are discussed. Different aspects of the reduction process such as the formation of intermediate tungsten oxides and β-W, the reactions of dopant-containing compounds and their effects on the reduction kinetics are summarized. A conclusion on the theories concerning the dopant incorporation during reduction is followed by a review of the technological relationships between the reduction parameters and the tungsten powder properties (e.g. grain size and dopant incorporation), as knowledge of these is essential for efficient process control. A further paper on ‘the reduction of NS-doped tungsten blue oxide’ will follow in this journal, based on the authors' own experimental experiences.