Power mixture and green body for producing silicon nitride base articles of high fracture toughness and strength

Patent · 17 September 1991

OSTI ID:7085450

Huckabee, M L; Buljan, S T; Neil, J T

A powder mixture and a green body for producing a silicon nitride-based article of improved fracture toughness and strength are disclosed. The powder mixture includes (a) a bimodal silicon nitride powder blend consisting essentially of about 10-30% by weight of a first silicon nitride powder of an average particle size of about 0.2 [mu]m and a surface area of about 8-12m[sup 2]g, and about 70-90% by weight of a second silicon nitride powder of an average particle size of about 0.4-0.6 [mu]m and a surface area of about 2-4 m[sup 2]/g, (b) about 10-50 percent by volume, based on the volume of the densified article, of refractory whiskers or fibers having an aspect ratio of about 3-150 and having an equivalent diameter selected to produce in the densified article an equivalent diameter ratio of the whiskers or fibers to grains of silicon nitride of greater than 1.0, and (c) an effective amount of a suitable oxide densification aid. The green body is formed from the powder mixture, an effective amount of a suitable oxide densification aid, and an effective amount of a suitable organic binder. No Drawings

• DOE Contract Number: AC05-84OR21400
• Assignee: GTE Laboratories Incorporated, Waltham, MA (United States)
• Patent Number(s): A; US 5049530
• Application Number: PPN: US 7-596256
• OSTI ID: 7085450
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360601* -- Other Materials-- Preparation & Manufacture
BINDERS
COMPACTING
COMPOSITE MATERIALS
CRYSTALS
FABRICATION
FIBERS
FRACTURE PROPERTIES
MATERIALS
MECHANICAL PROPERTIES
MONOCRYSTALS
NITRIDES
NITROGEN COMPOUNDS
ORGANIC COMPOUNDS
PARTICLE SIZE
PNICTIDES
SILICON COMPOUNDS
SILICON NITRIDES
SIZE
WHISKERS