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Correlating Microstructure with Backscattered Ultrasonic Energy

Published online by Cambridge University Press:  21 February 2011

John Mittleman
Affiliation:
Naval Coastal Systems Center Panama City, FL 32407
David W. Mohr
Affiliation:
Naval Coastal Systems Center Panama City, FL 32407
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Abstract

High frequency ultrasonic energy interacts with metallurgical microstructure to produce scattered energy fields that are useful in characterizing the material. By using a focused transducer whose focal spot size and ultrasonic wavelength are both comparable to the scale of grain structure in high purity copper specimens, the authors have shown a strong correlation between microstructure and the pattern of backscattered ultrasonic signals. A systematic series of experiments logged the ultrasonic returns from cold-rolled copper with the direction of the ultrasonic beam both parallel to and transverse to the rolling direction. Fourteen samples were annealed to various degrees, capturing several stages of recovery and recrystallization. Use of backscattered ultrasonic energy rather than specularly reflected energy allows isolation of grain boundary scattering in an otherwise quiet acoustic environment. Clear differences between returns of backscattered shear waves from parallel and transverse beam orientations relative to the rolling direction gradually disappear as the annealing process re-establishes a field of equiaxial crystals. Backscattered surface waves also show variations that appear to correspond with the relaxation of residual stresses before the onset of recrystallization, and preferred orientation after recrystallization.

Type
Research Article
Copyright
Copyright © Materials Research Society 1989

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References

[1] Hecht, A., Thiel, R., Neumann, E. and Mundry, E., “Nondestructive Determination of Grain Size in Austenitic Sheet by Ultrasonic Backscattering”, Mat. Eval., Vol.39, Sep 81, pp 934938 Google Scholar
[2] Billy, de, Michel, , and Laszlo, Adler, “Parameters Affecting Backscattered Ultrasonic Leaky-Rayleigh Waves from Liquid-Solid Interfaces”, J. Ac.Soc. Am. Vol.72, No. 3, Sep 82, pp 1018–1020CrossRefGoogle Scholar
[3] Adler, , Laszlo, , Billy, Michel de, and Quentin, Gerard J., “Excitation of Ultrasonic Rayleigh Leaky Waves at Liquid-Solid Interface for General Angle of Incidence”, J. Appl. Phys., Vol.53, No. 12, Dec 82, pp 8756–8758CrossRefGoogle Scholar
[4] Klinman, R. and Stephenson, E.T., “Ultrasonic Prediction of Grain Size and Mechanical Properties in Plain Carbon Steel”, Mat. Eval., Vol.39, Nov 81, pp 1116–1120Google Scholar
[5] Klinman, R., Webster, G.R.,, Marsh, F.J., and Stephenson, E.T., “Ultrasonic Prediction of Grain Size, Strength, and Toughness in Plain Carbon Steel”, Mat. Eval., Vol.38, Oct 80, pp 26–32Google Scholar
[6] Vary, A. and Hull, D.R., “Interrelation of Material Microstructure, Ultrasonic Factors, and Fracture Toughness of a Two-Phase Titanium Alloy”, Mat. Eval., Vol.41, March 83, pp 309–314Google Scholar
[7] Vary, A., “Correlations among Ultrasonic Propagation Factors and Fracture Toughness Properties of Metallic Materials”, Mat. Eval., Vol.36, Jun 78, pp 55–64Google Scholar
[8] Vary, A. “Concepts for Interrelating Ultrasonic Attenuation, Microstructure, and Fracture Toughness in Polycrystalline Solids”, Mat. Eval., Vol.46, Apr 88, pp 642–649Google Scholar
[9] Serabian, S. and Williams, R.S., “Experimental Determination of Ultrasonic Attenuation Characteristics Using the Roney Generalized Theory”, Mat. Eval., Vol.36, Jul 78, pp 55–62Google Scholar
[10] Green, , Robert, E. Jr. “Ultrasonic Investigation of Mechanical Properties”, Treatise on Materials Science and Technology (Volume 3), Academic Press, New York, 1973 Google Scholar
[11] Krautkramer, J. and Krautkramer, H., “Ultrasonic Testing of Materials”, Springer-Verlag, NY, 1969 CrossRefGoogle Scholar
[12] American Society for Metals, “Metals Handbook: Metallography and Microstructures (Volume 9)”, ASM, Metals Park, OH, 1985 Google Scholar
[13] Barrett, C.S., “Structure of Metals: Crystallographic Methods, Principles, and Data”, McGraw Hill, NY, 1952 Google Scholar