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Ultrasonic Characterization of Nonuniform Porosity Distributions in SiC Ceramic

  • Ken Telschow
  • John Walter
  • Dennis Kunerth

Abstract

During fabrication of monolithic ceramic silicon carbide very localized regions of high porosity can be produced. This porosity often consists of a very large density of small pores. Even at ultrasonic wavelengths considerably larger than the pore size, significant effects can be observed in ultrasonic wave propagation through these materials. These effects include attenuation, scattering, and changes in wave velocity. This paper describes the characterization of such a porosity distribution in SiC utilizing these ultrasonic techniques and their correlation with x-ray and optical microscopy measurements. Significant effects were observed due to the nonuniformity of the porosity, which resulted in enhancement of signal amplitudes greatly exceeding attenuation effects due to scattering. This unexpected result proved to be most sensitive to the boundaries of the porosity distribution and provided one of the best techniques for delineating its extent.

Keywords

Common Line Porosity Distribution Velocity Shift Ultrasonic Wave Propagation Radiographic Density 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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Copyright information

© Plenum Press, New York 1988

Authors and Affiliations

  • Ken Telschow
    • 1
  • John Walter
    • 1
  • Dennis Kunerth
    • 1
  1. 1.Idaho National Engineering LaboratoryEG&G Idaho, Inc.Idaho FallsUSA

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