Accession Number:

ADA270040

Title:

Experimental Investigation of Wave and Fracture Phenomena in Impacted Ceramics. Final Report: Experiments on Sapphire

Descriptive Note:

Journal article

Corporate Author:

FRAUNHOFER-INST FUER WERKSTOFFMECHANIK FREIBURG (GERMANY F R)

Personal Author(s):

Report Date:

1993-05-01

Pagination or Media Count:

81.0

Abstract:

Experiments have been performed in order to investigate the behavior of monocrystalline sapphire under impact loading. Tile shaped samples were hit edge-on by spherical or flat steel impactors. The generation of pressure waves and disintegration effect were observed by a Cranz-Schardin high speed camera. The results are compared with earlier ones obtained with glass and alumina as target material. A terminal crack velocity was not found. Crack velocities exceeding the Rayleigh wave speed have been measured. Similar as with glass, nucleations of cracks in the field between the primary wave front and the front of the disintegration area form a damage velocity which can approach the longitudinal wave speed. Usually, cracks did not follow crystal planes the influence of the crystal structure does not seem to be a strong one.

Subject Categories:

  • Geology, Geochemistry and Mineralogy
  • Ceramics, Refractories and Glass
  • Crystallography
  • Mechanics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE