Interfaces in silicon-carbide whisker-reinforced silicon-nitride-based composites: A high-resolution electron-microscopy study

Miscellaneous · Tue Jan 01 00:00:00 EST 1991

OSTI ID:7110475

Das Chowdhury, K

Four kinds of silicon nitride/silicon carbide (whisker) matrix composites synthesized from common starting materials, except the whiskers themselves, at the same processing conditions were investigated. The interfacial structure and chemistry of the existence of an interfacial layer at the interface will affect the mechanical properties of the composites, e.g., crack propagation under applied stress, profoundly. The chemical environment near the interface will change the local elastic moduli and flow stress and eventually the fracture toughness of the composite. High-resolution electron-imaging microscopy and high-spatial-resolution electron energy-loss nanospectroscopy were used to characterize the whisker/matrix and matrix grain-boundary interfaces in these composites both structurally and chemically. The presence of a 1.5 to 2 nm-wide discontinuous oxygen-rich amorphous layer at the four kinds of whisker/matrix interfaces and 0.5 to 2 nm-wide continuous oxygen-rich and nitrogen-depleted amorphous layer at the matrix grain-boundary interfaces examined appeared to be general phenomena.

• Research Organization: Arizona State Univ., Tempe, AZ (United States)
• OSTI ID: 7110475
• Resource Relation: Other Information: Thesis (Ph.D.)
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
COMPOSITE MATERIALS
INTERFACES
ELECTRON MICROSCOPY
MATRIX MATERIALS
SILICON CARBIDES
SILICON NITRIDES
WHISKERS
CARBIDES
CARBON COMPOUNDS
CRYSTALS
MATERIALS
MICROSCOPY
MONOCRYSTALS
NITRIDES
NITROGEN COMPOUNDS
PNICTIDES
SILICON COMPOUNDS
360602* - Other Materials- Structure & Phase Studies