Dynamic fracture characterization of Al2O3 and SiCw/Al2O3. Technical report

Technical Report · Sun Sep 01 04:00:00 EDT 1991

OSTI ID:6068105

Deobald, L R; Kobayashi, A S

In spite of many favorable properties, ceramics has severe disadvantages of brittleness and poor impact resistance due to its inherently low fracture toughness. An obvious method to improve the toughness of ceramic materials is through the use of composite techniques. The possible improved toughness due to the added ceramic whisker fibers should allow a graceful failure rather than a catastrophic failure of a ceramic component. Several mechanisms exist by which a ceramic matrix composite can exhibit superior toughness over the toughness of the matrix material. These mechanisms include crack bridging, fiber pullout, crack deflection mechanisms, microcrack shielding, and phase transformation. In crack bridging, intact whisker fibers bridge the space between the two crack faces of the matrix. Since the fibers apply a crack closure force behind the crack tip, addition energy is required to overcome this force and propagate the crack.

• Research Organization: Washington Univ., Seattle, WA (United States). Dept. of Mechanical Engineering
• OSTI ID: 6068105
• Report Number(s): AD-A-242187/3/XAB; UWA/DME/TR--91/7; CNN: N00014-87-K-0326
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360203* -- Ceramics
Cermets
& Refractories-- Mechanical Properties
360603 -- Materials-- Properties
ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
BRIDGES
BRITTLENESS
CARBIDES
CARBON COMPOUNDS
CERAMICS
CHALCOGENIDES
COMPOSITE MATERIALS
CRACKS
CRYSTALS
DYNAMICS
ENERGY
FAILURES
FIBERS
FRACTURE PROPERTIES
IMPACT STRENGTH
MATERIALS
MATRIX MATERIALS
MECHANICAL PROPERTIES
MECHANICAL STRUCTURES
MECHANICS
MONOCRYSTALS
OXIDES
OXYGEN COMPOUNDS
PHASE TRANSFORMATIONS
SHIELDING
SILICON CARBIDES
SILICON COMPOUNDS
WHISKERS