TY - GEN
T1 - Anisotropic ultrasonic attenuation in an AA 5754 aluminum hot band
AU - Man, Chi Sing
AU - Cai, Zhiqiang
AU - Donohue, Kevin D.
AU - Fei, Peixing
PY - 2006
Y1 - 2006
N2 - Herein a simple phenomenological theory that involves an effective viscosity tensor is developed for the analysis and interpretation of spectroscopic data of through-thickness ultrasonic resonance. Under this theory, the attenuation of each mode of through-thickness stress waves is proportional to the square of the resonance frequency, which indicates that this theory may be adequate for covering attenuation due to dislocation damping, but not for attenuation due to grain scattering. Ultrasonic attenuation of through-thickness shear waves in sheet samples of a continuous-cast AA 5754 aluminum hot band and its O-temper counterpart was measured with resonance EMATs. The frequency range in question was from 2 to 10 MHz. For the hot band, the attenuation of the two shear modes was found to be predominantly proportional to the square of the frequency. The viscosity constant pertaining to the fast shear mode was about 3 times that of the slow shear mode, suggesting a highly anisotropic dislocation structure in the hot band.
AB - Herein a simple phenomenological theory that involves an effective viscosity tensor is developed for the analysis and interpretation of spectroscopic data of through-thickness ultrasonic resonance. Under this theory, the attenuation of each mode of through-thickness stress waves is proportional to the square of the resonance frequency, which indicates that this theory may be adequate for covering attenuation due to dislocation damping, but not for attenuation due to grain scattering. Ultrasonic attenuation of through-thickness shear waves in sheet samples of a continuous-cast AA 5754 aluminum hot band and its O-temper counterpart was measured with resonance EMATs. The frequency range in question was from 2 to 10 MHz. For the hot band, the attenuation of the two shear modes was found to be predominantly proportional to the square of the frequency. The viscosity constant pertaining to the fast shear mode was about 3 times that of the slow shear mode, suggesting a highly anisotropic dislocation structure in the hot band.
KW - Dislocation damping
KW - Ultrasonic attenuation
KW - Ultrasound resonance spectroscopy
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M3 - Conference contribution
AN - SCOPUS:33845919656
SN - 0873396111
SN - 9780873396110
T3 - TMS Annual Meeting
SP - 35
EP - 44
BT - Aluminum Wrought Products for Automotive, Packaging, and other Applic. - The James Morris Honorary Symp. - Proc. of Symp. sponsored by the Reactive Metals Committee of the LMD of The Minerals, Metals
T2 - 135th TMS Annual Meeting, 2006
Y2 - 12 March 2006 through 16 March 2006
ER -