Protective coating for alumina-silicon carbide whisker composites

Patent · Tue Jun 13 00:00:00 EDT 1989

OSTI ID:5729823

Tiegs, T N

This patent describes a method for forming a protective coating on a ceramic composite consisting essentially of an alumina matrix having about 1 to 60 volume percent silicon carbide whiskers dispersed therein. It comprises: the steps of heating the composite in an oxidizing atmosphere to a temperature greater than about 1200{degrees} C., and maintaining the composite at temperature greater than about 1200{degrees} C. for a duration sufficient to form an essentially oxygen impervious coating of mullite or mullite plus silicon oxide and alumina on the surface of the composite for inhibiting oxidation of silicon carbide whiskers in the composite underlying the coating. This patent also describes a method for forming a protective coating on a ceramic composite consisting essentially of an alumina matrix having about 1 to 60 volume percent silicon carbide whiskers dispersed therein. It comprises the steps of coating exposed surface portions of the composite with a layer formed of a slurry of silicon oxide or silicon oxide and alumina.

• Assignee: Martin Marietta Energy Systems, Inc., Oak Ridge, TN
• Patent Number(s): US 4839316; A
• Application Number: PPN: US 7-112167A
• OSTI ID: 5729823
• Resource Relation: Patent File Date: 26 Oct 1987
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
COMPOSITE MATERIALS
SURFACE COATING
ALUMINIUM OXIDES
CERAMICS
HEAT TREATMENTS
MULLITE
PROTECTIVE COATINGS
SILICON CARBIDES
SILICON OXIDES
SLURRIES
WHISKERS
ALUMINIUM COMPOUNDS
CARBIDES
CARBON COMPOUNDS
CHALCOGENIDES
COATINGS
CRYSTALS
DEPOSITION
DISPERSIONS
INORGANIC ION EXCHANGERS
ION EXCHANGE MATERIALS
MATERIALS
MINERALS
MIXTURES
MONOCRYSTALS
OXIDE MINERALS
OXIDES
OXYGEN COMPOUNDS
SILICON COMPOUNDS
SUSPENSIONS
360201* - Ceramics
Cermets
& Refractories- Preparation & Fabrication