The Measurement of Viscoelastic Moduli Using an Ultrasonic Spectroscopy Technique

Hsiao, Chiuder; Kline, Ronald A.

doi:10.1109/ultsym.1984.198335

Cited by 5 publications

(1 citation statement)

References 3 publications

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“…(The effect of diffraction on the phase of the ultrasonic waveforms is small, and no corrections to phase were made (ref. 24). Ultrasonic images were constructed over a wide band of frequencies (e.g., 30 to 110 MHz, at 10-MHz intervals) from reflection coefficent, attenuation coefficient, and phase velocity values obtained at each scan point.…”

Section: Ultrasonic Contact Scanningmentioning

confidence: 99%

Quantitative Mapping of Pore Fraction Variations in Silicon Nitride Using an Ultrasonic Contact Scan Technique

Roth

Kiser

Swickard

et al. 1995

Research in Nondestructive Evaluation

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An ultrasonic scan procedure using the pulse-echo contact configuration was employed to obtain maps of pore fraction variations in sintered silicon nitride samples in terms of ultrasonic material properties. Ultrasonic velocity, attenuation coefficient, and reflection coefficient images were obtained simultaneously over a broad band of frequencies (e.g., 30 to 110 MHz) by using spectroscopic analysis. Liquid and membrane (dry) coupling techniques and longitudinal and shear-wave energies were used. The major results include the following: Ultrasonic velocity (longitudinal and shear wave) images revealed and correlated with the extent of average through-thickness pore fraction variations in the silicon nitride disks. Attenuation coefficient images revealed pore fraction nonuniformity due to the scattering that occurred at boundaries between regions of high and low pore fraction. Velocity and attenuation coefficient images were each nearly identical for machined and polished disks, making the method readily applicable to machined materials. Velocity images were similar for wet and membrane coupling. Maps of apparent Poisson's ratio constructed from longitudinal and shear-wave velocities quantified Poisson's ratio variations across a silicon nitride disk. Thermal wave images of a disk indicated transient thermal behavior variations that correlated with observed variations in pore fraction and velocity and attenuation coefficients.

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Section: Ultrasonic Contact Scanningmentioning

confidence: 99%