Accession Number : ADA323321

Title :   Experimental Investigation of Wave and Fracture Phenomena in Impacted Ceramics: Sapphire.

Descriptive Note : Final rept. Sep 90-May 93,

Corporate Author : FRAUNHOFER-INST FUER KURZZEITDYNAMIK - ERNST-MACH-INST WEIL AM RHEIN (GERMANY )

Personal Author(s) : Senf, H. ; Winkler, S.

PDF Url : ADA323321

Report Date : FEB 1997

Pagination or Media Count : 102

Abstract : This report documents the experimental investigation of wave and fracture phenomena in monocrystalline sapphire. This research includes comparisons with glass and complements the Ernst Mach Institut investigation of ceramics and glasses that was published subsequently in ARL-CR-214, 'Experimental Investigations of Wave and Fracture Phenomena in Impacted Ceramics and Glasses'. A detailed discussion of wave phenomena and fracture phenomena is included, as well as a discussion of an electric emission method for wave and fracture detection. The work was made possible by the state of the art, high speed photographic capability available at the Ernst Mach Institut, specifically two 24-spark Cranz Shradin cameras, which can be used both in transmission and reflectance. Sapphire tiles were impacted by both spherical and flat projectiles and the generation of pressure waves and disintegration effects were observed. Twenty four high quality photographic images could be obtained at predetermined time intervals of less than 1 microsecond.

Descriptors :   *FRACTURE(MECHANICS), *CERAMIC MATERIALS, *SAPPHIRE, *MECHANICAL WAVES, GLASS, ELECTRON EMISSION, GERMANY, REFLECTANCE, SPALLATION, PHOTOGRAPHIC IMAGES, SPARK SHADOWGRAPH PHOTOGRAPHY, TRANSMISSIONS(MECHANICAL), MICROCRACKING.

Subject Categories : Ceramics, Refractories and Glass
      Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE