Process for the manufacture of friable silicon nitride bodies

US5061416A · kind A · utility

Assignee

• Norton Company · US

Inventors

• Craig A. Willkens · Sterling, US
• Normand D. Corbin · Marlborough, US
• Brian J. Caprera · East Greenwich, US

Key dates

• Filing date: Oct 30, 1989
• Grant date: Oct 29, 1991
• Expiry date: Oct 30, 2009

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C01P2006/10
• WIPO field: Materials, metallurgy
• WIPO sector: Chemistry

Abstract

A friable silicon nitride body is prepared by infiltrating a non-friable silicon nitride body with a fluid which expands upon freezing, rapidly freezing the fluid, and thawing the frozen fluid. Silicon nitride flakes and chunks obtained with only light pressure on the friable body may then be final milled to a desired particle size more rapidly and with less energy input than with conventionally processed silicon nitride. The silicon nitride body may have a higher density than has previously been used to prepare silicon nitride powders, thereby preventing the generation of potentially hazardous whiskers in the final powder product.