Failure Prediction in Ceramics Using Ultrasonics.
Abstract
The requirements for failure prediction in ceramics using ultrasonics have been examined. These show that the absolute prediction of failure at acceptable stress levels and lifetimes requires high frequencies, in the 50-400 MHz range. The ability to utilize such high frequencies for flaw detection studies is primarily dependent on the attenuation of the material in this frequency range. Attenuation studies performed on a variety of ceramic materials have shown that the coarse grained or porous ceramics are excessively attenuating, whereas the fine grained fully dense ceramics are acceptable. An analysis of attenuation using numerical scattering cross sections and microstructural parameters has demonstrated that the attenuation is entirely predictable from the large extreme of the microstructure. The analysis has also suggested that attenuation measurements may permit the implementation of statistical failure prediction at high levels of confidence, in materials that are not amenable to absolute failure prediction using high frequency ultrasonics. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 17, 1976
- Accession Number
- ADA033004
Entities
People
- A. G. Evans
- B. R. Tittmann
- L. A. Ahlberg