ULTRASONIC SPECTROSCOPY OF STEEL,
Abstract
An electronic instrument has been developed which makes it possible to obtain the ultrasonic attenuation spectrum of a solid material. The spectroscope employs the ultrasonic pulse-echo test technique and is equipped with a single ultrasonic transducer which is used for both transmission and reception of ultrasonic signals. Special electronic circuitry provides improved uniformity of transducer frequency response with the result that a frequency range of 3 to 12 mc can be covered. The ultrasonic spectroscope has been applied to examine microstructures of steel specimens differently heat treated to produce grain size variations. Experimental results indicate that the amplitude distribution in the ultrasonic spectrum is strongly influenced by specimen microstructure. It is possible to discriminate between grain sizes varying from 2 to 8 (ASTM scale) on the basis of ultrasonic attenuation spectra observed. Compared with conventional multiple-back-echo attenuation testing, the spectroscopic method offers the advantage that measurements can be carried out much faster. A further feature of the technique is that the back-echo amplitude is not involved in the measurement and thus can be used as a control indication to continuously monitor overall equipment sensitivity and transducer coupling conditions. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1964
- Accession Number
- AD0614113
Entities
People
- Otto R. Gericke
Organizations
- United States Army Research Laboratory