Patent · US Expired

Silicon nitride vacuum furnace process

US4970057A · kind A · utility

94Cited by

0References

27Claims

0Family size

Assignee

Norton Company · US

Inventors

Craig A. Willkens · Sterling, US
Stephen D. Hartline · Shrewsbury, US
Normand P. Arsenault · Holden, US

Key dates

Filing date	Feb 14, 1990
Grant date	Nov 13, 1990
Priority date	—
Expiry date	Feb 14, 2010

Classification

Technology area (CPC C)Chemistry; Metallurgy
CPC primaryC01B21/0682
WIPO fieldMaterials, metallurgy
WIPO sectorChemistry

Abstract

An improved process of preparing silicon nitride by the direct nitridation of silicon metal is disclosed. The process is a multi-step one which is substantially more efficient than prior processes and produces a silicon nitride having an oxygen content of less than 1%, a silicon metal content of less than 0.5%, and an alpha phase content of at least 85%, preferably at least 90%. The silicon nitride may be converted to a powder.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.