Accession Number:

ADA242187

Title:

Dynamic Fracture Characterization of Al2O3 and SiCw/Al2O3

Descriptive Note:

Technical rept.,

Corporate Author:

WASHINGTON UNIV SEATTLE DEPT OF MECHANICAL ENGINEERING

Personal Author(s):

Report Date:

1991-09-01

Pagination or Media Count:

19.0

Abstract:

In spite its 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.

Subject Categories:

  • Laminates and Composite Materials

Distribution Statement:

APPROVED FOR PUBLIC RELEASE