CHARACTERISTIC PROPERTIES OF COBALT POWDER SUITABLE FOR HARD METAL PRODUCTION

Abstract

Prompted by the fact that knowledge of the essential properties of fine metallic powders, such as Co powder, used in hard metal production is often inadequate, this investigation uses a special working hypothesis. According to this the following properties of such a powder are most important: its SEM image, specific surface area, crystallite size as determined with X-rays, and α/β phase distribution. In the first part of this paper two well-known commercial Co powders are studied; in the second part methods of producing a fine Co powder from a special type of Co oxalate are described. The results show that it is feasible to produce a powder corresponding to the reference powders, provided that the crystal size and form of the oxalate are correctly developed and decomposition conditions (temperature, time) are right.