Method of manufacturing bodies of silicon nitride

US4455275A · kind A · utility

Assignee

• Asea AB

Inventors

• Jan Alderborn · Robertsfors, SE
• Hans Larker · Robertsfors, SE

Key dates

• Filing date: Oct 10, 1980
• Grant date: Jun 19, 1984
• Expiry date: Oct 10, 2000

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C04B35/593
• WIPO field: Materials, metallurgy
• WIPO sector: Chemistry

Abstract

Bodies of silicon nitride are produced by enclosing a silicon nitride powder in a gas-tight glass casing and subjecting the casing to isostatic pressure using gas as a pressure medium at a temperature of at least 1600.degree. C. and a pressure of at least 100 MPa. The casing is a glass having a high softening point. The casing is evacuated and sealed before compressing. The product may be pre-formed by isostatic compacting at a pressure of at least 100 MPa at a temperature considerably below the sintering temperature. The casing is cooled at a rate of at most 1000.degree. C. per hour and at a pressure of not over 10 MPa.