Measurement of Elastic Moduli of Materials at Elevated Temperature.
Annual summary rept. 16 Aug 69-15 Aug 70,
PANAMETRICS INC WALTHAM MA
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The objective of this program has been the investigation of the properties of solids at elevated temperatures by means of ultrasonic waves. Solids such as metals, ceramics, graphites, plastics, and composites have been tested. As it became apparent that attenuation of ultrasound was an important effect which could both interfere with velocity measurements and yield important information about the properties of matter, the measurement of attenuation became an important part of this program. Since ultrasonic attenuation and changes in elastic modulus are related by common causative mechanisms in many cases, it has become necessary to study both. Progress has been made in measuring both attenuation and velocity at temperatures up to 3000 K, with the range for velocity measurements alone extending to 3750 K. Several new methods for measuring attenuation have been introduced. These methods permit the simultaneous measurement of moduli, also. The methods can be used to yield attenuation as a function of frequency as well as of temperature or other parameters. Propagation of bulk waves longitudinal and transverse and wire waves extensional and torsional can be measured accurately.
- Metallurgy and Metallography