Gte Products Corporation

Martin Marietta Energy Systems, Inc.

Southern Illinois University

Dale E Wittmer

Robert W Wolfe

Terry N Tiegs

Robert J Dobbs

Robert A Long

Peter Filip

David E Thomas

Harrison Shallenberger

An intermetallic bonded diamond composite composition and methods of processing such a composition are provided by the present invention. The intermetallic bonded diamond composite composition preferably comprises a nickel aluminide (NiAl) binder and diamond particles dispersed within the nickel aluminide (NiAl) binder. Additionally, the composite composition has a processing temperature of at least about 1,200&#xb0; C. and is processed such that the diamond particles remain intact and are not converted to graphite or vaporized by the high-temperature process. Methods of forming the composite composition are also provided that generally comprise the steps of milling, pressing, and sintering the high-temperature intermetallic binder and diamond particles.

Intermetallic bonded diamond composite composition and methods of forming articles from same

A method for producing a high solids content, low viscosity ceramic slurry composition comprises turbomilling a dispersion of a ceramic powder in a liquid to form a slurry having a viscosity less than 100 centipoise and a solids content equal to or greater than 48 volume percent.

Method of preparing a high solids content, low viscosity ceramic slurry

A method is disclosed for producing silicon nitride wherein the crystal morphology is controlled. The method involves heating a mixture consisting essentially of a chlorosilane and ammonia at a sufficient temperature for a sufficient time to produce a nitogen containing silane as an intermediate. The bulk density of the intermediate is controlled to less than about 0.1 g/cc to result in the silicon nitride having a crystal morphology which is essentially all fibrous, or the bulk density can be controlled to greater than about 0.3 g/cc to result in the silicon nitride having a crystal morphology which is essentially all equiaxial, or the bulk density can be controlled to between about 0.1 g/cc and about 0.3 g/cc to result in the silicon nitride having a crystal morphology which is a mixture of fibrous and equiaxial. The intermediate is then heated at a sufficient temperature for a sufficient time in a non-oxidizing atmosphere to produce the controlled crystal morphology silicon nitride.

Method for controlling the crystal morphology of silicon nitride

A process is disclosed for producing beta silicon nitride fibers. The process involves heating a green article of a silicon nitride based material in a furnace at a temperature of from about 1700.degree. C. to about 2000.degree. C. at a pressure of nitrogen gas of at least about 100 psig for a sufficient time to form silicon nitride fibers, the major portion of which are beta silicon nitride fibers. The heating step is carried out with the article covered with a cover made of silicon carbide or silicon nitride. Alternately, the article can be in a container of silicon nitride or silicon carbide and covered with the cover.

Process for producing beta silicon nitride fibers

An article is disclosed comprising particles of a silicon nitride based material and a lubricating material, the lubricating material occupying interconnected spaces within the article, the spaces being at least about 3% by volume of the article.

Self lubricating silicon nitride article

A silicon nitride based cutting tool is disclosed consisting essentially of in percent by weight about 5% aluminum oxide, about 6% yttrium oxide, from about 1.5% to about 5.5% silicon dioxide, and the balance silicon nitride, and having a density of at least about 99% of the theoretical density.

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Carbondale, IL, United States of America

Dale E Wittmer