Location

Ithaca, NY

Start Date

1978 12:00 AM

Description

A high frequency 250 MHz A-scan system has been used for flaw detection. We have been able to detect 25-500 ~m defects of different types (C, Si, SIC, BN, Fe, WC) in a Si3N4 plate. Since it is difficult to determine the defect type and size from the amplitude of the backscattered signal , we have carried out Fourier transforms of the backscattered signal to obtain reflectivity as a function of frequency, and used that information to characterize the size and type of defect. Our ea~ly experiments have been with voids in glass and Si 3N4 and we are able to predict the size of the defects we detect.

Book Title

Proceedings of the ARPA/AFML Review of Progress in Quantitative NDE

Chapter

7. Reliability of Structural Ceramics

Pages

237-240

Language

en

File Format

application/pdf

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Jan 1st, 12:00 AM

High Frequency Ultrasonics

Ithaca, NY

A high frequency 250 MHz A-scan system has been used for flaw detection. We have been able to detect 25-500 ~m defects of different types (C, Si, SIC, BN, Fe, WC) in a Si3N4 plate. Since it is difficult to determine the defect type and size from the amplitude of the backscattered signal , we have carried out Fourier transforms of the backscattered signal to obtain reflectivity as a function of frequency, and used that information to characterize the size and type of defect. Our ea~ly experiments have been with voids in glass and Si 3N4 and we are able to predict the size of the defects we detect.