Ultrasonic probes using shear-wave crystals—principles

GGLYAMINA, I. P. and CHULKOVA, V. K. An ultrasonic transducer with a clamped ferrite core. Akusticheskii Zhurnal,Vol 13,No 4 (October-December 196’7) pp623 -625 Detailed measurements have shown that ferrite 21 (a material of Soviet manufacture) can be used in such transducers without appreciable reduction in the conversion factor, provided u lies between 150 and 300kg/cm2. The device has the advantage that the frequency can be adjusted by altering the clamping. (Ultrasonics 1968, abstract 759) GGGDMAN,J.E.and LAW,D.W. Ultrasonic descaling and desoaping of wire. Wire Industry, Vol 34,No 407 (November 1967) ~1275 After a brief outline of the basic principles of ultrasonics and the phenomenon of cavitation, the methods are discussed by which ultrasonic techniques can assist the wire manufacturer. Practical examples are given, and several installations are described in detail. The applications described include deaning prior to plating in a wire mill, the elimination of excessive pickling fumes, and descaling high and low carbon rods. The removal of drawing lubricants from various types of wire is also covered. (Ultrasonic 1968, abstract 760) GROMOV,N.P.,MYASNIKOV,L.L.andMYASNIKOVA,E.N. Ultrakunds in speech. Akusticheskii Zhurnal, Vol 13, No 4 (October-December 1967) ~~627-628 An experimental investigation was carried out into the ultrasonic components of speech up to 16OkHz. Vowels and consonants do not have a clearly defined ultrasonic spectrum. Ultrasound is most clearly represented for sibilants for which the ultrasonic spectrum is a characteristic feature. Both Russian and Polish speech sounds were investigated. (Ultrasonics 1968, abstract 761) HIGGS,R. W. and TORBORG,R. II. Ultrasonic absorption in carbon dioxide/water vapour mixtures. Journal of the Acoustical Society of America, Vol 42,No 5 (November 1967) ~1038 The absorption of ultrasound in CO,/H,O mixtures at 150@ and 2009= was measured at frequencies of 1.25,3.3, 4.8,9. 9 and 14. OMHz for Ha0 concentrations from 0. 5% to 50%. The measured absorptions are compared with calculated results and agree reasonably well. The effect of Hz0 vapour on the relaxation frequency is linear, at least up to 20% Hz0 vapour, and a decrease in relaxation frequency is observed with increasing temperature. (Ultrasonics 1968, abstract 762) HOLTON,G.,HAGELBERG,M.P.,KAO,S.andJOHNSON,W.H. (Jr) Ultrasonic velocity measurements in water at pressures up to lO,OOOkg/cm2. Journal of the Acoustical Society of America, Vol 43, No 1 ‘(January 1968) ~102 Measurements of the velocity of ultrasonic pulses in water are presented for pressures up to about 10, 000kg/cm2 and for temperatures up to 80%. Coefficients obtained from leastsquares polynomial fittings of the data are also given,together with an analysis of the reliability and reproducibility of the experimental results. (Ultrasonics 1968, abstract 763) HUNTER, J. L. and DERDUL, P. R. Acoustic absorption and dynamic viscosity in a long-chain polymer. Journal of the Acoustical Society of America, Vol 42,No 5 (November 1967) ~1041 Acoustic absorption has been measured in the 200 series of silicones (linear polysiloxanes) over a frequency range 30-350MHz and a temperature range-30” to + 30°C. The results are compared with measurements of dynamic viscosity made in the same fluids by Barlow,Harrison and Lamb in approximately the same experimental region. It is found that knowledge of the dynamic viscosity enables one to predict, quite precisely, the value of the acoustic absorption coefficient. The negligible volume viscosity and surprisingly low values of acoustic absorption and dynamic viscosity in this experimental range are discussed in terms of the theories of Rouse and Zimm for polymeric liquids of very long chain lengths. (Ultrasonics 1968, abstract 764) 130

ULTRASONICS April 1968

KOPPELMAN, J. Ultrasonic measurement of hardening depth in steel rolls Materialpriifung,Vol 9, No 11 (November 1967) pp401-405 It is possible to obtain information on the grain size of a polycrystalline material as a function of the distance from the surface by measuring the backscattering of ultrasonic pulses from grain boundaries using high-.sensitivity ultrasonic detectors. Sufficient accuracy for practical measurements can be reached if the statistical backscattering of sound waves (noise by grain boundaries) is averaged by moving the transceiver probe in a suitable manner. Measurements on hardened steel rolls at the frequencies 30 and 6OMHz are discussed. It is shown that the hardening depth can be determined by non-destructive ultrasonic inspection. (Ultrasonics 1968, abstract 765)

LOVELACE, J. F. and LUINI, L. A. A correlation study betweenultrasonic, radbgrqhic andvisual examinationof heavy steel plate weldments. Materials Evaluation,Vol 26,No 1 (January 1968) ppl-7 Data are presented from the radiographic and ultrasonic inspection (both manual and automatic) of 16 HY-80 steel plate butt welds. The results of visual examination of 95 sections cut from eight of the welds are compared with radiographic and ultrasonic inspection data at these locations. The validity of the ultrasonic inspection process was found to be almost twice as great as the validity of the radiographic inspection process. Results of the visual examination are discussed in relation to theory. (Ultrasonics 1968, abstract 766)

LYNNWORTH, L.C. Ultrasonic probes using shear-wave crystals-principles. Materials Evaluation, Vol 25, No 12, (December 1967) ~~265-277 The potential scope of ultrasonic shear-wave testing has generally not yet been exploited because of the inherent limitations of existing bonding, mode conversion or other highly specialized coupling methods. Such shortcomings are substantially avoided by means of pressure or optical contact coupling of SV and SH shear waves at oblique incidence. Since shear waves interact with materials and stress in a manner different from longitudinal waves, shear waves can be used to determine materials properties which are difficult or impossible to obtain with longitudinal waves. Testing possibilities are grouped according to whether the incident shear wave enters the specimen normally or obliquely. Applications of shear waves include measurements of temperature, thickness and flaws at elevated temperature, shear wave inspection and characterization of low velocity materials, and determination of stress, strain and material orientations which are sensitive to shear wave polarization. Additional unique advantages of incident shear waves are obtained by mode conversion to Rayleigh, Lamb, longitudinal and Love waves. These waves, in turn, may be applied to Rayleigh, Lamb and Love wave inspection at high frequencies, above lOMHz, or in low velocity solids such as graphites or plastics. Longitudinal wave tests in fluids may be accomplished in extreme environments by using a shear-wave buffer rod to isolate the crystal from the exposed portion of the probe. Longitudinal waves can also be refracted more favourably with respect to certain thermometry and flow measurement problems by using an obliquely incident shear wave. (Ultrasonics 1968, abstract 767;

MAURO, R. A method for measuring the transducer frequency response of an ultrasonic amplifier. Proceedings of the Institute of ’ Electrical and Electronics Engineers, Vol 55, No 12 (December 1967) ~~2195-2196 A technique for the measurement of the transducer frequency, response in an ultrasonic amplifier, using the acoustoelectric effect, is presented. The validity of this method is experiment ally verified by using the measured transducer characteristics to predict the amplifier transmission and comparing this result with the actual transmission data. (Ultrasonics 1968, abstract 768)