Abstract:
A technique is presented for In-situ measurement of the longitudinal wave velocity in ceramic powder compacts undergoing sintering. The technique uses laser generation and contact detection of the ultrasonic signal. Results are presented for sintering zinc oxide and alumina. The data demonstrate the capability for performing in-situ longitudinal wave velocity measurements at high temperatures, and in attenuative materials such ceramic powder compacts. In addition, the data demonstrate the sensitivity of ultrasonic velocity measurements to changes within the sintering compact which are not detectable by dimension measurement alone. A novel interprot0tlOn of the ultrasonic velocity data is also presented. This interpretation is based upon analysis of the longitudinal wave velocity data In the context of existing modes treating surface area reduction during sintering. A previously observed correlation between the longitudinal wave ultrasonic velocity and the specific surface area facilitates the analysis. Activation energies for Surface area reduction during sintering which were determined by this tochniqu0 compare well with values reported in the literature.
(Ref. SXVIII-015-97)
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.
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