Method of forming a silicon nitride article

摘要

A method for forming a silicon nitride article is set forth. An article having silicon particles therein is formed in a manner which provides a degree of porosity for the article. The silicon particles of the article are reactable with nitrogen to form silicon nitride. The article is heated to a temperature below a significant reaction temperature at which nitrogen gas reacts with the silicon particles at a measurable rate. The article is surrounded with an atmosphere containing nitrogen gas. A reaction zone is established on at least a portion of the surface area of the article. The reaction zone has a temperature above the significant reaction temperature whereby the silicon particles in the reaction zone are reacted at a measurable rate with the nitrogen gas to form silicon nitride. The reaction zone is moved in a controlled manner from the surface of the article into the interior of the article whereby the article is progressively nitrided inwardly into its bulk from the surface thereof.