Accession Number : ADA325054

Title :   Photothermal Imaging of Indentation in Silicon Nitride.

Descriptive Note : Final technical rept.,

Corporate Author : PHYSICAL-TECHNICAL INST ST PETERSBURG (RUSSIA)

Personal Author(s) : Muratikov, Kyrill l. ; Glazov, Alexej L.

PDF Url : ADA325054

Report Date : SEP 1996

Pagination or Media Count : 23

Abstract : Theoretical model for determination of temperature distribution in ceramics with a lateral crack is developed for a case of photothermal measurements of indentation cracks. The lateral crack is modeled by a horizontal buried layer with a given thermal resistance. A possible penetration of the pump beam light in ceramics is taken into account. The dependence of photo acoustic and photodeflection signals on the thermal resistance and pump beam light in ceramics are investigated. Photodeflection and piezoelectric images of indentation cracks in silicon nitride have been obtained. It is shown that these images have different structure and can be used for the development of a complex approach to the problem of indentation crack imaging in silicon nitride ceramics.

Descriptors :   *CRACKS, *CERAMIC MATERIALS, *ACOUSTIC SIGNALS, *SILICON NITRIDES, MATHEMATICAL MODELS, LASER PUMPING, LASER BEAMS, IMAGES, PIEZOELECTRIC MATERIALS, RUSSIA, THERMAL RESISTANCE, PHOTOTHERMAL PROPERTIES.

Subject Categories : Ceramics, Refractories and Glass
      Acoustics
      Mechanics
      Thermodynamics

Distribution Statement : APPROVED FOR PUBLIC RELEASE