Effect of basic powder particle properties on densification of porous tungsten.

Porous tungsten is employed extensively for components such as dispenser cathodes in electronic valves and light technology. Normally parts are produced by die pressing or cipping and sintered in a reducing atmosphere at temperatures • 2000°C. In this study, the aim was to look critically at the behaviour of tungsten powder at compaction and sintering so that the distribution of porosity could be better controlled and optimised. Attention was focused on the basic powder properties, such as particle size and shape, surface area and apparent density. The effects of these parameters on the relative density of the parts are described. A small quantity of aluminium was added to the tungsten powder to serve as a binder and a potential sintering aid. [ABSTRACT FROM AUTHOR]