Elevated-temperature-delayed failure of alumina reinforced with 20 vol% silicon carbide whiskers

Journal Article · Mon Jan 01 04:00:00 EST 1990 · Journal of the American Ceramic Society; (USA)

DOI:https://doi.org/10.1111/j.1151-2916.1990.tb05096.x· OSTI ID:6785564

Becher, P F; Angelini, P; Warwick, W H; Tiegs, T N ^[1]

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1. Oak Ridge National Lab., TN (USA). Metals and Ceramics Div.

Alumina composites reinforced with 20 vol% SiC whiskers were exposed to applied stresses in four- point flexure at temperatures of 1000{degrees}, 1100{degrees}, and 1200{degrees}C in air for periods of up to 14 weeks. At 1000{degrees} and 1100{degrees}C, an apparent fatigue limit was established at stresses of {approx}75% of the fast fracture strength. However, after long-term ({gt}6 weeks) tests at 1100{degrees}C, some evidence of crack generation as a result of creep cavitation was detected. At 1200{degrees}C applied stresses as low as 38% of the 1200{degrees}C fracture strength were sufficient to promote creep deformation and accompanying cavitation and crack generation and growth resulting in failures in times of {lt}250 h.

• DOE Contract Number: AC05-84OR21400
• OSTI ID: 6785564
• Journal Information: Journal of the American Ceramic Society; (USA), Journal Name: Journal of the American Ceramic Society; (USA) Vol. 73:1; ISSN 0002-7820; ISSN JACTA
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360203* -- Ceramics
Cermets
& Refractories-- Mechanical Properties
ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
CARBIDES
CARBON COMPOUNDS
CHALCOGENIDES
CRACK PROPAGATION
CREEP
CRYSTALS
MATERIALS
MECHANICAL PROPERTIES
MONOCRYSTALS
OXIDES
OXYGEN COMPOUNDS
REINFORCED MATERIALS
SILICON CARBIDES
SILICON COMPOUNDS
STRESSES
VERY HIGH TEMPERATURE
WHISKERS