Characteristics of Acoustic Emission Signals from Ceramics.
Abstract
Acoustic emission bursts generated during slow and rapid crack growth in a variety of polycrystalline ceramics as well as twinning and rapid crack growth in sapphire were characterized by their number, amplitude, pulse shape, and frequency content. The microstructures and fracture surface features of the specimens were examined and correlations were made between these features and the characteristics of the acoustic emissions bursts. Nine materials were studied covering a range of preparation techniques, compositions, and grain sizes. These included alumina from three sources, magnesia from three sources, plus spinel, porcelain, and silicon nitride from one source each. A variety of types of frequency spectra of the individual acoustic emission bursts were observed which in some cases could be identified with a specific generation process such as crack-twin interaction or step-wise transgranular cleavage. (Modified author abstract)
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 22, 1974
- Accession Number
- AD0778015
Entities
People
- George A. Alers
- Lloyd J. Graham