manufacture of u00fcbergangsmetallkarbid, u00fcbergangsmetallnitrid and u00fcbergangsmetallkarbonitridwhiskern

摘要

The present invention relates to a method of producing, in large volumes and at low cost, Ta-, Nb-, Zr- and Hf- carbide, nitride or carbonitride whiskers, preferably submicron, having excellent reinforcing properties, suitable as reinforcement in a wide range of materials, including metals, intermetallics, plastics, ceramics and metallic bonded hard material. Oxides of Ta, Nb Zr and Hf or alkalicompounds thereof in amount to satisfy the stoichiometric requirements of the desired carbide or nitride is mixed with the carbon source along with an alkali and/or alkaliearth metal halogenide as a volatilization agent for the metal and a catalyst for the whisker growth such as Ni and/or Co. The reactant powders are blended in some typical manner using a high speed blender so as to intimately mix them. Finally, the starting material is subjected to nitriding, carbonising or carbonitriding heat treatments in order to produce the desired whiskers. IMAGE