Electron microscopy of interfaces in silicon carbide whisker-reinforced alumina composites

Conference · Mon Jan 01 04:00:00 EST 1990

OSTI ID:7171303

Alexander, K B; Angelini, P; Becher, P F

Knowledge about the nature of interfaces between SiC whiskers and alumina matrices is critical to understanding the mechanical behavior of these types of composites. The fracture toughness, in particular, is strongly influenced by the bond characteristics of this interface. Previous results have shown that oxidizing the whiskers in air prior to composite fabrication by vacuum hot-pressing results in composites which have lower toughness compared to those made with whiskers in the as-received condition. This investigation focusses on the effects of oxidizing and reducing surface treatments on the whiskers themselves and on the whisker-matrix interface. High resolution electron microscopy (HREM) was used to characterize the morphology and the amount of amorphous phase at the whisker-matrix interface, as well as the crystallography and topography of the interface. The present results indicate that the characteristics of the whisker/matrix interface may not be directly related to the initial whisker surface chemistry. Surprisingly, the thickest thermally-grown oxide layer resulted in the thinnest amorphous film at the SiC/Al{sub 2}O{sub 3}interface. 9 refs., 9 figs.

• Research Organization: Oak Ridge National Lab., TN (USA)
• Sponsoring Organization: DOE/ER
• DOE Contract Number: AC05-84OR21400
• OSTI ID: 7171303
• Report Number(s): CONF-900466-35; ON: DE90010439
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360602* -- Other Materials-- Structure & Phase Studies
360603 -- Materials-- Properties
360604 -- Materials-- Corrosion
Erosion
& Degradation
ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
CARBIDES
CARBON COMPOUNDS
CHALCOGENIDES
CHEMICAL REACTIONS
CRYSTALS
ELECTRON MICROSCOPY
FRACTURE PROPERTIES
INTERFACES
MATERIALS
MECHANICAL PROPERTIES
MICROSCOPY
MONOCRYSTALS
OXIDATION
OXIDES
OXYGEN COMPOUNDS
REINFORCED MATERIALS
SILICON CARBIDES
SILICON COMPOUNDS
SURFACE TREATMENTS
WHISKERS