Nondestructive Evaluation of Thermally Shocked Silicon Carbide by Impact-Acoustic Resonance
Author:
Bemis R. A.1, Shiloh K.2, Ellingson W. A.3
Affiliation:
1. Caterpillar, Inc., Peoria, IL 60482 2. Soreq Nuclear Research Center, Yavne, Israel 3. Argonne National Laboratory, Argonne, IL 60439
Abstract
Monolithic ceramics are under consideration as structural components for hot-stage sections of gas-fired turbine engines. In addition to manufacturing quality control, other important aspects for this application include life prediction modeling and time between engine overhauls. One nondestructive evaluation (NDE) method that provides information about material condition involves an analysis of resonant vibrations. In previous work by this general approach, changes in modal parameters have been related to bulk defect mechanisms such as microcracking due to thermal shock damage. In this work resonant vibrations from monolithic ceramic specimens were excited by an instrumented impact hammer and detected by a noncontact acoustic microphone over frequencies up to 100 kHz. Computer-based analysis of vibration signatures from test specimens allowed extraction of modal frequencies and damping constants. Downward shifts in detected resonant frequencies and increases in internal friction or (specific) damping capacity measurements were obtained from SiC cylindrical rings, and these measurements were shown to relate to thermal shock severity. This NDE method not only provides measurable parameters that could be used as accept–reject criteria for in-line process inspection, it also provides a means for tracking the mechanical integrity of in-service engine components to support life prediction modeling.
Publisher
ASME International
Subject
Mechanical Engineering,Energy Engineering and Power Technology,Aerospace Engineering,Fuel Technology,Nuclear Energy and Engineering
Reference8 articles.
1. Bemis, R. A., 1994, “Digital Signal Processing for Non-destructive Evaluation of Ceramics Using Impact-Acoustic Response Measurements,” M.S.E.E. Thesis, Illinois Institute of Technology, Chicago, IL. 2. Chu, Y. C., Hefetz, M., and Rokhlin, S. I., 1993, “Ultrasonic Assessment of Microcrack Damage in Ceramics,” Review of Progress in Quantitative Nondestructive Evaluation, Plenum Press, New York, pp. 2175–2182. 3. Copolla
J. A.
, and BradtR. C., 1973, “Thermal-Shock Damage in SiC,” Journal of the American Ceramic Society, Vol. 56, No. 4, pp. 214–218. 4. Coppack, T. J., 1980, “A Method for Thermal Cycling Refractories and an Appraisal of Its Effect by a Nondestructive Technique,” read at the Edinburgh meeting of the Refractories Section, Sept. 10. 5. Iwasaki, K., 1991, “Improvement of FFT Spectra by Synchronization of Input Signal at First and Last Zero-Crossing Points,” Proc. Fifth International Symposium on Nondestructive Characterization of Materials, Karuizawa, Japan, sympositum sponsored by Iketani Science and Technology Foundation, pp. 233–243.
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