Title: High-Temperature Ultrasonic Sensor for In Situ Nondestructive Testing of Ceramics

Abstract:
A sensor has been developed and tested that is capable of emitting and receiving ultrasonic energy at temperatures exceeding 900°C (1652°F) and pressures above 150 MPa (22,500 psi). The sensor is based on a unique form of alumium nitride that retains the piezoelectric properties at high temperatures and work with standard ultrasonic pulser-receiver. High temperature/high pressure operation was demonstrated through operation of the sensor inside a hot iostatic pressing (HIP) vessel at 940°C at a pressure of 150 MPa. Details of the sensor design, performance, and coupling of the ultrasound to the workpiece will be presented. Ultrasonic data acquired by the sensor, in situ, during high temperature HIT runs and at elevated temperatures in air will be presented. It is anticipated that the sensor will be useful for the control of a variety of high temperature processes as well as for material characterization/NDE at elevated temperatures.
(Ref. SXVIII-016-97)

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