Process for preparing a densified beta-phase silicon nitride material having at least one densification aid, and the material resulting therefrom

Patent · Tue May 25 04:00:00 EDT 1993

OSTI ID:6543203

Edler, J P; Lisowsky, B

A process is described for preparing an alpha-phase silicon nitride material and thereafter sintering to a densified beta-phase silicon nitride material, comprising: (a) comminuting a slurry including a mixture of (i) silicon-containing powder, (ii) water, and (iii) at least one densification aid to aid in later densifying of the silicon nitride material, said comminuting being performed to form fresh, non-oxidized surfaces on the silicon powder and to allow substantial chemical reaction between the silicon and the water, said comminuting being performed to form fresh, non-oxidized surfaces on the silicon powder and to allow substantial chemical reaction between the silicon and the water, yielding a mass; (b) nitriding the mass by exposure to a sufficient amount of a nitriding gas including at least nitrogen at a sufficient temperature for a sufficient length of time to form a mass of substantially alpha-phase silicon nitride; and (c) sintering the resultant silicon nitride mass at a sintering holding temperature of from about 1,450 C to about 2,100 C for a sufficient length of time to convert the silicon nitride from a predominantly alpha-phase material to a predominantly densified beta phase silicon nitride material exhibiting a decrease in bulk volume of the silicon nitride due to the densification.

• Assignee: Eaton Corporation, Cleveland, OH (United States)
• Patent Number(s): A; US 5213729
• Application Number: PPN: US 7-557371
• OSTI ID: 6543203
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360201* -- Ceramics
Cermets
& Refractories-- Preparation & Fabrication
CHEMICAL REACTIONS
COMMINUTION
CRYSTAL STRUCTURE
DENSITY
DISPERSIONS
ELEMENTS
FABRICATION
MICROSTRUCTURE
MIXTURES
NITRIDATION
NITRIDES
NITROGEN
NITROGEN COMPOUNDS
NONMETALS
PHYSICAL PROPERTIES
PNICTIDES
POWDERS
SILICON COMPOUNDS
SILICON NITRIDES
SINTERING
SLURRIES
SUSPENSIONS
TEMPERATURE RANGE
TEMPERATURE RANGE 1000-4000 K