Abstract
A model is presented which relates the absolute backscattered noise level observed in an ultrasonic immersion inspection to details of the measurement system and properties of the metal specimen under study. The model assumes that the backscattered noise signal observed for a given transducer position is an incoherent superposition of echoes from many grains. The model applies to normal-incidence, pulse-echo inspections of weakly-scattering materials using toneburst pulses from either a planar or focused transducer. The model can be used in two distinct ways. Measured noise echoes can be analyzed to deduce a “Figure-of-Merit” (FOM) which is a property of the specimen alone, and which parameterizes the contribution of the microstructure to the observed noise. If the FOM is known, the model can be used to predict the absolute noise levels that would be observed under various inspection scenarios. Tests of the model are reported, using both synthetic noise echoes, and measured noise echoes from metal specimens having simple and complicated microstructures.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
A. B. Bhatia,Ultrasonic Absorption (Chap. 11) (Clarendon Press, Oxford, 1967).
K. Goebbels, Structure analysis by scattered ultrasonic radiation inResearch Techniques in Nondestructive Testing, R. S. Sharpe, ed. (Academic Press, New York, 1980), pp. 87–157.
B. R. Tittmann and L. Ahlberg, Attenuation and grain noise parameters in Ni-base alloys inReview of Progress in Quantitative NDE, Vol. 2A, D. O. Thompson and D. E. Chimenti, eds. (Plenum Press, New York, 1983), pp. 129–145.
P. B. Nagy, D. V. Rypien, and L. Adler, Ultrasonic attenuation measurement by backscattering analysis inReview of Progress in Quantitative NDE, Vol. 6B, D. O. Thompson and D. E. Chimenti, eds. (Plenum Press, New York, 1987), pp. 1411–1417.
P. B. Nagy and L. Adler, Scattering induced attenuation of ultrasonic backscattering, inReview of Progress in Quantitative NDE, Vol. 7B, D. O. Thompson and D. E. Chimenti, eds. (Plenum Press, New York, 1988), pp. 1263–1271.
E. L. Madsen, M. F. Insana, and J. A. Zagzebski, Method of data reduction for accurate determination of acoustic backscatter coefficients,J. Acoust. Soc. Am. 76:913–923 (1984).
M. F. Insana, E. L. Madsen, T. J. Hall, and J. A. Zagzebski, Tests of accuracy of a data reduction method for determination of acoustic backscatter coefficients,J. Acoust. Soc. Am. 79:1230–1236 (1986).
T. J. Hall, E. L. Madsen, J. A. Zagzebski, and E. J. Boote, Accurate depth-independent determination of acoustic backscatter coefficients with focused transducers,J. Acoust. Soc. Am. 85:2410–2416 (1989).
F. J. Margetan, T. A. Gray, and R. B. Thompson, A technique for quantitatively measuring microstructurally induced ultrasonic noise, inReview of Progress in Quantitative NDE, Vol. 10B, D. O. Thompson and D. E. Chimenti, eds. (Plenum Press, New York, 1991), pp. 1721–1728.
F. J. Margetan and R. B. Thompson, Microstructural noise in titanium alloys and its influence on the detectability of hard-alpha inclusions,Review of Progress in Quantitative NDE, Vol. 11B, D. O. Thompson and D. E. Chimenti, eds. (Plenum Press, New York, 1992), pp. 1717–1724.
M. D. Russell, S. P. Neal, and E. J. Boote, Experimental estimation of the longitudinal-wave backscatter coefficients for ultrasonic interrogation of weak scattering materials,J. Acoust. Soc. Am. 93:1267–1276 (1993).
M. D. Russell and S. P. Neal, Experimental estimation of the transverse-wave backscatter coefficients for ultrasonic interrogation of weak scattering materials,J. Acoust. Soc. Am. (to be published).
M. D. Russell and S. P. Neal, Grain noise power spectrum estimation for weak scattering polycrystalline materials using experimentally estimated backscatter coefficients: Normal incidence,Ultrasonics (to be published).
M. D. Russell and S. P. Neal, Grain noise power spectrum estimation for weak scattering polycrystalline materials using experimentally estimated backscatter coefficients: Oblique incidence,Ultrasonics (submitted).
F. J. Margetan, R. B. Thompson, I. Yalda-Mooshabad, and Y. K. Han, Detectability of Small Flaws in Advanced Engine Alloys, U.S. Air Force Technical Report, Center for NDE, Iowa State University, Ames, Iowa (1993).
F. Amin, T. A. Gray, and F. J. Margetan, A new method to estimate the effective geometric focal length and radius of ultrasonic focused probes, inReview of Progress in Quantitative NDE, Vol. 10A, D. O. Thompson and D. E. Chimenti, eds. (Plenum Press, New York, 1991), pp. 861–865.
Specimen PWL was supplied by Pratt & Whitney Aircraft, West Palm Beach, Florida; Specimens A1, A2, B2, and C1 were supplied by General Electric AEBG, Cincinnati, Ohio.
I. Yalda-Mooshabad, F. J. Margetan, and R. B. Thompson, Monte-Carlo simulation of ultrasonic grain noise, inReview of Progress in Quantitative NDE, Vol. 12B, D. O. Thompson and D. E. Chimenti, eds. (Plenum Press, New York, 1993), pp. 1727–1734.
R. B. Thompson and T. A. Gray, A model relating ultrasonic scattering measurements through liquid-solid interfaces to unbounded medium scattering amplitudes,J. Acoust. Soc. Am. 74:1279 (1983).
B. A. Auld, General electromechanical reciprocity relations applied to the calculation of elastic wave scattering coefficients,Wave Motion 1:3 (1979).
J. H. Rose, Ultrasonic backscatter from microstructure, inReview of Progress in Quantitative NDE, Vol. 11B, D. O. Thompson and D. E. Chimenti, eds. (Plenum Press, New York, 1992), pp. 1677–1684.
J. H. Rose, Theory of ultrasonic backscatter from multiphase polycrystalline solids, inReview of Progress in Quantitative NDE, Vol. 12B, D. O. Thompson and D. E. Chimenti, eds. (Plenum Press, New York, 1993), pp. 1717–1726.
R. Bracewell,The Fourier Transform and Its Applications (Chap.12) (McGraw-Hill, New York, 1965).
P. H. Rodgers and A. L. Van Buren, An exact expression for the Lommel diffraction integral,J. Acoust. Soc. Am. 55:724–728 (1974).
M. Abramowitz and I. A. Stegun,Handbook of Mathematical Functions (Chap. 9) (Dover, New York, 1965).
R. B. Thompson and T. A. Gray, Range of applicability of inversion algorithms, inReview of Progress in Quantitative NDE, Vol. 1, D. O. Thompson and D. E. Chimenti, eds. (Plenum Press, New York, 1982), pp. 233–249.
R. B. Thompson and E. F. Lopes, The effects of focusing and refraction on Gaussian ultrasonic beams,J. Nondestr. Eval. 4:107 (1984).
B. P. Newberry and R. B. Thompson, A paraxial theory for the propagation of ultrasonic beams in anisotropic solids,J. Acoust. Soc. Am. 85:2290–2300 (1989).
K. Y. Han, R. B. Thompson, F. J. Margetan, and J. H. Rose, Relationship between ultrasonic noise and macrostructure of titanium alloys, inReview of Progress in Quantitative NDE, Vol. 12, D. O. Thompson and D. E. Chimenti, eds. (Plenum Press, New York, 1993), pp. 1743–1750.
J. M. M. Pinkerton, A pulse method for the measurement of ultrasonic absorption in liquids: Results for water,Nature 160:128 (1947).
Yan Li and R. B. Thompson, Relations between elastic constantsC ij and texture parameters for hexagonal materials,J. Appl. Phys. 67(5):2663–2665 (1990).
R. B. Thompson, J. F. Smith, S. S. Lee, and G. C. Johnson, Comparison of ultrasonic and X-ray determinations of texture in thin Cu and Al plates,Metall. Trans. A 20A:2431–2447 (1989).
J. A. Ogilvy, Ultrasonic beam profiles and beam propagation in an austenitic weld using a theoretical ray tracing model,Ultrasonics 24:337 (1986).
F. J. Margetan, R. B. Thompson, and I. Yalda-Mooshabad, Modeling ultrasonic microstructural noise in titanium alloys, inReview of Progress in Quantitative NDE, Vol. 12B, D. O. Thompson and D. E. Chimenti, eds. (Plenum Press, New York, 1993), pp. 1735–1742.
F. J. Margetan, R. B. Thompson, and I. Yalda-Mooshabad, Estimating ultrasonic signal-to-noise ratios for inspections of cylindrical billets, inReview of Progress in Quantitative NDE, Vol. 13B, D. O. Thompson and D. E. Chimenti, eds. (Plenum Press, New York, 1994), pp. 1737–1744.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Margetan, F.J., Thompson, R.B. & Yalda-Mooshabad, I. Backscattered microstructural noise in ultrasonic toneburst inspections. J Nondestruct Eval 13, 111–136 (1994). https://doi.org/10.1007/BF00728250
Received:
Revised:
Issue Date:
DOI: https://doi.org/10.1007/BF00728250