Specialized metallurgical processes – compositions for use therei – Compositions – Consolidated metal powder compositions
Patent
1998-01-13
1999-12-28
Wyszomierski, George
Specialized metallurgical processes, compositions for use therei
Compositions
Consolidated metal powder compositions
75240, 75246, 75252, C22C 2908
Patent
active
060075988
ABSTRACT:
A transition metal carbide-Group VIII metal powder comprising discrete particles of a transition metal carbide and Group VIII metal wherein: substantially all of the particles have a size of at most 0.4 micrometer; the transition metal carbide is selected from carbides of the group consisting of tungsten, titanium, tantalum, molybdenum, zirconium, hafnium, vanadium, niobium, chromium, mixtures and solid solutions thereof; and the Group VIII metal is selected from the group consisting of iron, cobalt, nickel, mixtures and solid solutions thereof. Said powders are produced by heating an admixture comprising a finishing source of carbon (e.g., acetylene black), a source of a group VIII metal (e.g., Co.sub.3 O.sub.4), and a particulate precursor to a temperature of about 1173 K to about 1773 K for a time sufficient to form a transition metal carbide-Group VIII metal powder, wherein at least about 25% by weight of the carbide precursor is carburized in forming the transition metal carbide of the transition metal carbide-Group VIII metal powder. The particulate precursor generally contains less than 2.5% oxygen by weight and contains compounds which undergo carburization such as a transition metal (e.g., W), lower valence transition metal carbide (W.sub.2 C) to form the transition metal carbide (e.g., WC)-Group VIII metal powder.
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Dunmead Stephen D.
Romanowski Michael J.
OMG Americas, Inc.
Wyszomierski George
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