Title: NON-CONTACT ULTRASONIC ANALYSIS OF CERAMICS AND COMPOSITES

Abstract:
Conventional wisdom stipulates that ultrasonic analysis of ceramics and other solids cannot be accomplished without direct or delayed transducer contact with test materials. Thus Non-Contact Ultrasonic (NCU) Analysis, i.e., through air coupling, is viewed as impossible because of phenomenal acoustic impedance mis-match between the coupling air and the test media. After several years of struggle, at Ultran we have successfully broken this arduous ultrasonic barrier. This facilitates the propagation of ultrasound waves (<200KHz to 5MHz) through low and high density ceramics and other materials without transducer contact. By utilizing NCU, in this paper we shall provide several examples of imaging, velocity-density relationships, and defect detection in green and sintered ceramics and composites. Also provided will be the status of NCU, its potential in industrial materials reliability, process control, and opportunities in materials R&D.
(Ref. SXVIII-018-97)

Source: NDE of Ceramics '97 May 4-7, Symposium on Nondestructive Evaluation of Ceramics at the American Ceramic Society 99th Annual Meeting, Cincinnati, Ohio.
Buying the Symposium Proceedings from the American Ceramic Society.