Protective coating for alumina-silicon carbide whisker composites
Abstract
Ceramic composites formed of an alumina matrix reinforced with silicon carbide whiskers homogenously dispersed therein are provided with a protective coating for preventing fracture strength degradation of the composite by oxidation during exposure to high temperatures in oxygen-containing atmospheres. The coating prevents oxidation of the silicon carbide whiskers within the matrix by sealing off the exterior of the matrix so as to prevent oxygen transport into the interior of the matrix. The coating is formed of mullite or mullite plus silicon oxide and alumina and is formed in place by heating the composite in air to a temperature greater than 1200.degree. C. This coating is less than about 100 microns thick and adequately protects the underlying composite from fracture strength degradation due to oxidation.
- Inventors:
-
- Lenoir City, TN
- Issue Date:
- Research Org.:
- Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
- OSTI Identifier:
- 867000
- Patent Number(s):
- 4839316
- Assignee:
- United States of America as represented by United States (Washington, DC)
- Patent Classifications (CPCs):
-
C - CHEMISTRY C04 - CEMENTS C04B - LIME, MAGNESIA
- Resource Type:
- Patent
- Country of Publication:
- United States
- Language:
- English
- Subject:
- protective; coating; alumina-silicon; carbide; whisker; composites; ceramic; formed; alumina; matrix; reinforced; silicon; whiskers; homogenously; dispersed; therein; provided; preventing; fracture; strength; degradation; composite; oxidation; exposure; temperatures; oxygen-containing; atmospheres; prevents; sealing; exterior; prevent; oxygen; transport; interior; mullite; plus; oxide; heating; air; temperature; 1200; degree; 100; microns; thick; adequately; protects; underlying; due; dispersed therein; protective coating; ceramic composites; ceramic composite; silicon carbide; silicon oxide; carbide whiskers; microns thick; oxygen-containing atmosphere; fracture strength; carbide whisker; containing atmosphere; sites formed; -silicon carbide; matrix reinforced; /428/427/501/
Citation Formats
Tiegs, Terry N. Protective coating for alumina-silicon carbide whisker composites. United States: N. p., 1989.
Web.
Tiegs, Terry N. Protective coating for alumina-silicon carbide whisker composites. United States.
Tiegs, Terry N. Sun .
"Protective coating for alumina-silicon carbide whisker composites". United States. https://www.osti.gov/servlets/purl/867000.
@article{osti_867000,
title = {Protective coating for alumina-silicon carbide whisker composites},
author = {Tiegs, Terry N},
abstractNote = {Ceramic composites formed of an alumina matrix reinforced with silicon carbide whiskers homogenously dispersed therein are provided with a protective coating for preventing fracture strength degradation of the composite by oxidation during exposure to high temperatures in oxygen-containing atmospheres. The coating prevents oxidation of the silicon carbide whiskers within the matrix by sealing off the exterior of the matrix so as to prevent oxygen transport into the interior of the matrix. The coating is formed of mullite or mullite plus silicon oxide and alumina and is formed in place by heating the composite in air to a temperature greater than 1200.degree. C. This coating is less than about 100 microns thick and adequately protects the underlying composite from fracture strength degradation due to oxidation.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Sun Jan 01 00:00:00 EST 1989},
month = {Sun Jan 01 00:00:00 EST 1989}
}