Processing and characterization of SiC-whisker-reinforced alumina-matrix composites

Journal Article · Sun Jan 31 23:00:00 EST 1993 · Journal of the American Ceramic Society; (United States)

DOI:https://doi.org/10.1111/j.1151-2916.1993.tb03813.x· OSTI ID:6300816

Smith, S M; Singh, J P ^[1]; Scattergood, R O ^[2]

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1. Argonne National Lab., IL (United States)
2. North Carolina Univ., Raleigh, NC (United States). Dept. of Materials Science and Engineering

Brittle monolithic alumina can be reinforced with high-strength single-crystal SiC whiskers with the effect of increasing fracture toughness. In this study, well-mixed and nearly fully dense SiC whisker/alumina composites were fabricated by wet-blending the constituents and uniaxially hot-pressing the resulting powder. The alumina-matrix grain size depended on whisker volume fraction, whisker surface-oxygen content, and hot-pressing environment. Fracture toughness, measured by an indentation-fracture method, increased from 3.0 MPa[center dot]m[sup [1/2]] for the hot-pressed unreinforced alumina to 10.7 MPa[center dot]m[sup [1/2]] for the composite containing 25 vol% SiC whiskers. Fracture surfaces revealed evidence of toughening by the mechanisms of crack deflection, pullout, and crack bridging by the whiskers. The observed increase in fracture toughness of alumina due to the addition of SiC whiskers was correlated with existing models of toughening mechanisms.

• OSTI ID: 6300816
• Journal Information: Journal of the American Ceramic Society; (United States), Journal Name: Journal of the American Ceramic Society; (United States) Vol. 76:2; ISSN 0002-7820; ISSN JACTAW
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360601* -- Other Materials-- Preparation & Manufacture
360603 -- Materials-- Properties
ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
CARBIDES
CARBON COMPOUNDS
CHALCOGENIDES
COMPOSITE MATERIALS
CRYSTALS
ELECTRON MICROSCOPY
FABRICATION
FRACTURE PROPERTIES
GRAIN SIZE
HOT PRESSING
MATERIALS
MATERIALS WORKING
MATRIX MATERIALS
MECHANICAL PROPERTIES
MICROSCOPY
MICROSTRUCTURE
MONOCRYSTALS
MONOMERS
OXIDES
OXYGEN COMPOUNDS
POWDERS
PRESSING
PROCESSING
REINFORCED MATERIALS
SCANNING ELECTRON MICROSCOPY
SILICON CARBIDES
SILICON COMPOUNDS
SIZE
WHISKERS