Union Oil Company of California

Advanced Industrial Materials

Sandvik Ab

Roy T Coyle

Phillman N Ho

Rick J Orth

Richard D Tait

Dongxin Qi

Jan Magnus Ekelund

The presently claimed invention relates to a method of producing, in large volumes and at low cost, transition metal carbide, nitride or carbonitride whiskers, preferably submicron, having excellent reinforcing properties. These whiskers are suitable for use as a reinforcement in a wide range of materials, including metals, intermetallics, plastics, ceramics and metallic bonded hard material. The basic idea is the use of a carbon source with a volatile part which volatiles at temperatures up to 1000.degree. C. Transition metal oxide or alkali compounds thereof in amounts to satisfy the stoichiometric requirements of the desired carbide or nitride is mixed with the carbon powder along with an alkali metal chloride powder as a volatilization agent for the metal and a catalyst for the whisker growth such as Ni 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 or carbonitride whiskers

A process for producing silicon carbide whiskers in which a particulate form of carbon is combined with a silicon component, a boron component and seeding component to form a mixture which is then subjected to temperatures above about 1300.degree. C. in a nonoxidizing atmosphere such that carbon reacts with silica to form silicon carbide whiskers. The preferred particulate carbon, silicon component, boron component and seeding component are, respectively, carbon black, fumed silica, boron oxide and cobalt, iron or nickel. The size and shape of the whiskers can be controlled by varying the size of the seeding component and the concentration of the boron component.

Production of silicon carbide whiskers using a seeding component to

A processing for producing silicon carbide whiskers in which a source of silica is mixed with a residual oil or crude petroleum and the resultant mixture is heated in a substantially nonoxidizing atmosphere at temperature sufficiently high to carbonize the residual oil or crude petroleum, thereby forming an intimate mixture of carbon and silica. The intimate mixture is then heated in a nonoxidizing atmosphere in the presence of a seeding component comprising an element selected from the group consisting of boron, the rare earths, Group IA, Group IB, Group VB, Group VIB, Group VIIB and Group VIII of the Periodic Table of Elements at temperatures sufficiently high to induce the reaction between carbon and silica to form silicon carbide. The resultant silicon carbide product will contain a relatively high concentration of silicon carbide whiskers.

Process for producing silicon carbide whiskers using seeding agent

Silicon carbide is produced by a method which includes dispersing silica in a residual oil, carbonizing the oil at elevated temperatures, and heating the carbonized dispersion to form silicon carbide. Preferably, the silica is an amorphous type. Preferred residual oils are produced by distilling away crude petroleum components at temperatures up to about 350.degree. C. The silicon carbide product typically contains a mixture of powder and whisker configurations, and has many particles with a dimension less than about 1 micrometer.

Dispersions of silica in carbon and a method of making such dispersions

Silicon carbide is produced by a method which includes dipsersing silica in a residual oil, carbonizing the oil at elevated temperatures, and heating the carbonized dispersion to form silicon carbide. Preferably, the silica is an amorphous type. Preferred residual oils are produced by distilling away crude petroleum components at temperatures up to about 350.degree. C. The silicon carbide product typically contains a mixture of powder and whisker configurations, and has many particles with a dimension less than about 1 micrometer.

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Yorba Linda, CA, United States of America

Roy T Coyle