Applications and Advantages of Dry Coupling Ultrasonic Transducers for Materials Characterization and Inspection

  • J. A. Brunk
  • C. J. Valenza
  • M. C. Bhardwaj

Abstract

Practical self-coupling (dry coupling) piezoelectric ultrasonic transducer designs have been optimized for center frequencies up to at least 25MHz for longitudinal wave generation and at least 20MHz for zero degree incidence shear wave generation. While originally developed for examination of materials which would be damaged by liquid contact, they have been found to have practical and technical advantages for many materials characterization, discontinuity evaluation and gaging requirements.

Saving the time which would otherwise be required for the application and removal of liquid couplant is the most obvious advantage. Liquid intrusion is likely to cause unreliable data from porous materials and other materials which absorb water. Self-coupling facilitates the examination of assemblies with components such as electronic circuitry which could be damaged by liquids. Proper application of couplant is quite tedious for zero degree incidence shear wave examinations. Verification of complete removal of couplant is required where residue could interfere with subsequent processes such as chemical milling. For examination of low acoustic impedance materials, self-coupling provides increased transmission of ultrasonic energy into the test object and also improved near-surface resolution. Examples of several types of advantageous applications will be presented.

Keywords

Longitudinal Wave Delay Line Acoustic Impedance Test Surface Petroleum Jelly 
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.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. 1.
    J. A. Brunk, Applications of Dry Contact Ultrasonic Transducers, in: “Proceedings of the 11th World Conference on Nondestructive Testing, Vol. 2,” The American Society for Nondestructive Testing, Columbus, (1985).Google Scholar
  2. 2.
    J. A. Brunk, “An Investigation of Dry-Contact Ultrasonic Gaging, BDDX_613_3421,” U. S. Dept. of Energy, Washington, DC (1986)Google Scholar
  3. 3.
    J. A. Brunk, Performance Comparisons of Dry Coupling with Conventional Contact Ultrasonic Transducers, 0.5 – 20MHz, in: “Proceedings of the 16th Symposium on Nondestructive Evaluation,” NTIAC, San Antonio (1987).Google Scholar
  4. 4.
    J. A. Brunk, “An Investigation of Dry-Coupled Ultrasonic Thickness Gaging,” paper presented at the American Society for Nondestructive Testing Spring Conference, Phoenix (1987)Google Scholar
  5. 5.
    M. C. Bhardwaj, “Advances in Ultrasound for Materials Characterization,” paper presented at the 89th Meeting of the American Ceramic Society. Pittsburgh (1987).Google Scholar
  6. 6.
    J. A. Brunk, C. J. Valenza, and M. C. Bhardwaj, “Ultrasonic Characterization of Ceramics by Dry Coupling Techniques,” presented at the 89th Meeting of the American Ceramic Society, Pittsburgh (1987)Google Scholar
  7. 7.
    M. C. Bhardwaj, Principles and Methods of Ultrasonic Characterization of Materials. Adv Ceram Matls 1 (1986).Google Scholar
  8. 8.
    M. C. Bhardwaj, An Industrialist’s Perspective on Ultrasonic Characterization of Materials, J of Wave — Matl Inter 1:3 (1986).Google Scholar

Copyright information

© Springer Science+Business Media New York 1988

Authors and Affiliations

  • J. A. Brunk
    • 1
  • C. J. Valenza
    • 2
  • M. C. Bhardwaj
    • 2
  1. 1.Ultran Laboratories, Inc.Overland ParkUSA
  2. 2.Ultran Laboratories, Inc.State CollegeUSA

Personalised recommendations