Effectiveness of Monazite Coatings in Oxide/Oxide Composites after Long-Term Exposure at High Temperature
The effectiveness of monazite (LaPO4) in providing an oxidation‐resistant weak fiber/matrix interface was evaluated in a fiber roving/thin coating/ceramic‐matrix composite with >20% fiber volume fraction. Nextel™ 610/monazite/alumina composites were fabricated and tensile tested after isothermal...
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Published in | Journal of the American Ceramic Society Vol. 86; no. 2; pp. 325 - 332 |
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Main Authors | , , , , , |
Format | Journal Article |
Language | English |
Published |
Westerville, Ohio
American Ceramics Society
01.02.2003
Blackwell Wiley Subscription Services, Inc |
Subjects | |
Online Access | Get full text |
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Summary: | The effectiveness of monazite (LaPO4) in providing an oxidation‐resistant weak fiber/matrix interface was evaluated in a fiber roving/thin coating/ceramic‐matrix composite with >20% fiber volume fraction. Nextel™ 610/monazite/alumina composites were fabricated and tensile tested after isothermal exposures of up to 1000 h. Some strength loss was seen after short‐term exposures (1100°–1200°C/5–250 h); however, no further loss was observed after 1000 h at 1200°C. Conversely, control samples containing uncoated fiber displayed >70% strength losses after only 5 h at 1200°C. Fiber pullout was seen in monazite‐containing samples even after 1000 h at 1200°C. Debonding was predominantly in the coating or at either the fiber/coating or coating/matrix interface. Push‐out testing confirmed the weakness of the monazite coating interface. |
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Bibliography: | ark:/67375/WNG-41L4LHHC-F ArticleID:JACE325 istex:E647A916F6EB4573B5ECD1094190E64E15DBB338 UES, Inc., Dayton, OH, under USAF Contract No. F33615‐01‐C‐5214. Member, American Ceramic Society. ObjectType-Article-2 SourceType-Scholarly Journals-1 ObjectType-Feature-1 content type line 23 |
ISSN: | 0002-7820 1551-2916 |
DOI: | 10.1111/j.1151-2916.2003.tb00018.x |