Sandvik Ab

Advanced Industrial Materials

Mats Johnsson

Mats Nygren

Magnus Ekelund

Niklas Ahlen

Gunnar Brandt

R Tom Coyle

There is disclosed a method of producing, in large volume and at low cost, titanium carbide, nitride and carbonitride whiskers, with preferably submicron diameters, to be used as reinforcing material. The whiskers are suitable for use as a reinforcement material in a wide range of materials, including metals, intermetallics, plastics, ceramics and metallic bonded hard material. Titanium oxide, hydroxide or alkali compounds thereof are mixed with a carbon source with a volatile part which volatiles at temperatures exceeding 500.degree. C. and in an amount to satisfy the stoichiometric requirements of the carbide or nitride. A halogenide salt is used as a volatilization agent for titanium as well as a catalyst able to dissolve Ti plus C and/or N, such as Ni or Co. The reactant powders are blended in some typical manner, e.g., by using a high speed blender so as to intimately mix them. Finally, the mixed starting material is subjected to nitriding, carbonizing or carbonitriding heat treatments in order to produce the desired whiskers.

Manufacture of titanium carbide, nitride and carbonitride whiskers

There is disclosed 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 alkali compounds thereof in an amount to satisfy the stoichiometric requirements of the desired carbide or nitride are mixed with the carbon source along with an alkali and/or alkali earth 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, carbonizing or carbonitriding heat treatments in order to produce the desired whiskers.

Manufacture of transition metal carbide, nitride and carbonitride

There is disclosed a method of producing whiskers in large volumes and at low cost to be used as reinforcing material. The whiskers are solid solutions between two or more transition metal carbides, nitrides and carbonitrides, (Me.sub.1-X-Y.sub.Me'.sub.X+Y)C.sub.1-Z N.sub.Z, having preferably submicron diameters, where Me' is one or more transition metals other than Me. The whiskers are suitable for use as a reinforcement material in a wide range of materials, including metals, intermetallics, plastics, ceramics and metallic bonded hard material. Transition metal oxides, hydroxides or alkali compounds thereof are mixed with carbon powder. The carbon source is added in an amount to satisfy the stoichiometric requirements of the carbide or nitride. A halogenide salt is used as a volatilization agent for the transition metals and a catalyst such as Ni or Co that is able to dissolve transition metals plus C and/or N. The reactant powders are blended so as to intimately mix them. Finally, the mixed starting material is subjected to nitriding, carbonizing or carbonitriding heat treatments in order to produce the desired whiskers.

Growing community of inventors

Hagersten, Sweden

Mats Johnsson