Temperature dependence of strengthening by whisker reinforcement: SiC whisker-reinforced alumina in air

Journal Article · Tue Mar 01 04:00:00 EST 1988 · Advanced Ceramic Materials; (USA)

DOI:https://doi.org/10.1111/j.1551-2916.1988.tb00189.x· OSTI ID:6112007

Becher, P F; Tiegs, T N ^[1]

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1. Oak Ridge National Lab., TN (USA)

The high fracture toughness of alumina reinforced with 20 vol% SiC whiskers is maintained at temperatures up to {approx} 1,100{degree}C in air. The fracture strength values ({sigma}{sub f}) decrease slowly with increasing temperature to 1,100{degree}C; however, when subjected to an applied stress (= 2/3 {sigma}{sub f}) for periods of up to 1,000 h in air at 800{degree}, 1,000{degree}, or 1,100{degree}C, the subsequent fracture strength values (retained strengths) at these temperatures increase with increasing exposure times. On the other hand, above 1,100{degree}C, the fracture strength values decrease while the apparent toughness value increases. At 1,200{degree}C, samples first subjected to applied stresses of {le} 310 MPa for up to {approx} 240 h exhibit a loss in retained strengths with increasing exposure time. The temperature dependence of the mechanical behavior is shown to be related to oxidation reactions in these composites with creep phenomena contributing to the loss in strength and increased toughness above 1,100{degree}C.

• OSTI ID: 6112007
• Journal Information: Advanced Ceramic Materials; (USA), Journal Name: Advanced Ceramic Materials; (USA) Vol. 3:2; ISSN 0883-5551; ISSN ACEME
• 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
CREEP
CRYSTALS
DATA
EXPERIMENTAL DATA
FRACTURE PROPERTIES
INFORMATION
MEASURING METHODS
MECHANICAL PROPERTIES
MONOCRYSTALS
NUMERICAL DATA
OXIDES
OXYGEN COMPOUNDS
SILICON CARBIDES
SILICON COMPOUNDS
TEMPERATURE DEPENDENCE
VERY HIGH TEMPERATURE
WHISKERS