Title :
Nondestructive evaluation of graphite by ultrasonic velocity measurement using cross-correlation and Hilbert transform methods
Author :
Guerjouma, R. El ; Mouchtachi, A. ; Jayet, Y. ; Baboux, J.C.
Author_Institution :
Lab. Traitement de Signal et Ultrasons, Villeurbanne, France
Abstract :
The suitability of ultrasonics for materials evaluation of graphite components is investigated. The ultrasonic velocity is measured using cross-correlation techniques and a method based on the Hilbert transform of the pulse response function. The measurements are made on different grades of graphite with different particle sizes and porosities. Comparison of the two methods shows similar results for the graphites having small particle size and low attenuation. For large particle size and highly attenuating graphites, the measured quantities are different. The velocities and some identified elastic constants are correlated with the physical properties of the material (grain size and porosity) on specific examples in order to show the ability and the limits of ultrasonics to evaluate large grain size graphite
Keywords :
acoustic signal processing; correlation methods; graphite; particle size; transforms; ultrasonic materials testing; ultrasonic velocity; Hilbert transform methods; US NDE; cross-correlation; elastic constants; grain size; graphite components; highly attenuating graphites; low attenuation graphites; particle size; porosity; pulse response function; ultrasonic velocity; Acoustic materials; Acoustic propagation; Attenuation measurement; Calcination; Grain size; Particle measurements; Pulse measurements; Size measurement; Ultrasonic variables measurement; Velocity measurement;
Conference_Titel :
Ultrasonics Symposium, 1992. Proceedings., IEEE 1992
Conference_Location :
Tucson, AZ
Print_ISBN :
0-7803-0562-0
DOI :
10.1109/ULTSYM.1992.275868
