Two=stage prodn. of ultrafine metal composite powder

摘要

Ultrafine composite powder for use in the mfr. of sintered hard metals is mfd. by a two-step process involving: (a) mixing together tungsten oxide, cobalt oxide (specific surface area above 7.5 m<2>/g) and chromium oxide (with or without added "vanadium oxide raw material"); and (b) reducing the mixed oxide to a composite metal. "Vanadium oxide raw material" is obtd. by: (a) heating a mixt. of vanadium oxide and cobalt oxide to form a mixed oxide; then (b) partially reduced to form an oxide-metal composite powder.