University of California

The United States of America As Represented by the United States

The United States of America As Represented by the Department of Energy

J Birch Holt

Gregory M Bianchini

Michael D Kelly

Donald D Kingman

Donald D Kingman, Deceased

Disclosed is a method of producing dense refractory products, comprising:

Combustion synthesis method and products

Disclosed is a process for producing wurtzitic or cubic boron nitride comprising the steps of:

Process for producing wurtzitic or cubic boron nitride

A combustion synthesis process for the preparation of .alpha.-silicon nitride and composites thereof is disclosed. Preparation of the .alpha.-silicon nitride comprises the steps of dry mixing silicon powder with an alkali metal azide, such as sodium azide, cold-pressing the mixture into any desired shape, or loading the mixture into a fused, quartz crucible, loading the crucible into a combustion chamber, pressurizing the chamber with nitrogen and igniting the mixture using an igniter pellet. The method for the preparation of the composites comprises dry mixing silicon powder (Si) or SiO.sub.2, with a metal or metal oxide, adding a small amount of an alkali metal azide such as sodium azide, introducing the mixture into a suitable combustion chamber, pressurizing the combustion chamber with nitrogen, igniting the mixture within the combustion chamber, and isolating the .alpha.-silicon nitride formed as a reaction product.

Synthesis of fine-grained .alpha.-silicon nitride by a combustion process

Plasma spraying methods of forming exoergic structures and coatings, as well as exoergic structures produced by such methods, are provided. The methods include the plasma spraying of reactive exoergic materials that are capable of sustaining a combustion synthesis reaction onto a flat substrate or into molds of arbitrary shape and igniting said plasma sprayed materials, either under an inert gas pressure or not, to form refractory materials of varying densities and of varying shapes.

Processes for forming exoergic structures with the use of a plasma and

A one step combustion process for the synthesis of dense aluminum nitride compositions is disclosed. The process comprises igniting pure aluminum powder in a nitrogen atmosphere at a pressure of about 1000 atmospheres or higher. The process enables the production of aluminum nitride bodies to be formed directly in a mold of any desired shape.

Growing community of inventors

San Jose, CA, United States of America

J Birch Holt