SU1093967A1 - Method of ultrasonic checking of structure of uniform heterogenic solid materials - Google Patents

Abstract

METHOD FOR ULTRASONIC TESTING OF STRUCTURES UNIFORMLY heterogeneous solid materials, comprising, in a controlled material emit ultrasonic pulses, receiving bottom / signal and measured its amplitude which distinguishes the fact that, in order noBbmieni accuracy control, receiving reflected from the material structure pulse ultrazvukovk oscillations whose propagation time is less than the duration of the bottom signal propagation over its duration, measure the maximum amplitude of this pulse, compare it with a slab bottom signal and the comparison result (A determined controlled variable.

Description

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The invention relates to non-destructive testing and can be used in ultrasonic testing of products to determine the shape of inclusions.

The method of controlling the structure of materials is known, namely, that ultrasound is emitted into the controlled material, the first and second echo signals are received, the time of their reception is measured, and from this time the structure of the Cl 3 material is judged.

The disadvantage of this method is the impossibility of its use for controlling the shape of inclusions.

The closest in technical essence and the achieved result to the invention is the method of ultrasonic control of the structure of uniformly heterogeneous solid materials consisting in the fact that they emit ultrasonic pulses into the controlled material, receive the first and second bottom pulses, measure their amplitudes The shape of C 21 inclusions is determined. A disadvantage of this method is the high measurement error, reaching ten percent, due to diffraction phenomena Mi in the sample and unstable. By acoustic contact. The purpose of the invention is to increase the accuracy of the control. The goal is achieved by agreeing to the method of ultrasound monitoring of the strand of uniformly heterogeneous. solid materials, which imply that ultrasound pulses are emitted into the controlled material, receive the bottom signal and measure its amplitude, receive a pulse of ultrasonic vibrations reflected from the material structure, the propagation time of which is less than the time of the bottom signal propagation the amplitude of this pulse is compared with the amplitude of the bottom signal

and a controlled parameter is determined from the comparison result.

The control method is carried out as follows.

Ultrasonic pulses are emitted into controlled material. Take the bottom signal and structural noise from the heterogeneity of the structure of the material. The amplitude of the dong: 1st signal and the maximum amplitude of the structural sound of materials with a reception time shorter than the time of reception of the bottom signal no longer than the duration of the excited pulse are measured. The interval in which the maximum amplitude of structural noise is measured is chosen from a compromise: the impulse of structural noise should not merge with the bottom signal and the signal-to-noise ratio should be measured at one point in space. In this case, the amplitude of structural noise depends on the parameters of the piezotransducer, the distance from the reflection point, the acoustic parameters of the material under study and the acoustic contact, the amplitude of the bottom signal — on the parameters of the piezotransducer, the distance from the reflection point and acoustic contact. The ratio of measured amplitudes is calculated, which depends only on the acoustic parameters of the material itself — the velocity of propagation of ultrasonic waves and the scattering coefficient, the values of which depend on the structure of the material, namely, on the shape and size of the inclusions. This ratio is compared with the pre-hpBO4HbiN & i values and, based on a comparison, judges the shape of the inclusions. Thus, the method of ultrasonic control of the structure of uniformly heterogeneous solid materials allows to increase the accuracy of control. by eliminating inaccuracies caused by instability of acoustic contact and diffraction phenomena, by comparing the amplitudes of the bottom pulse and the pulse of structural noise.

Claims (1)

METHOD OF ULTRASONIC CONTROL OF THE STRUCTURE OF UNIFORMLY HETEROGENEOUS SOLID MATERIALS, which consists in the fact that ultrasonic pulses are emitted into the controlled material, the bottom / signal is measured and its amplitude is measured, which differs from the fact that, in order to increase the control accuracy, the ultrasound reflected from the structure of the material is received oscillations, the propagation time of which is less than the burden of propagation of the bottom signal for its duration, measure the maximum amplitude of this pulse, compare it with the amplitude d On the other hand, the controlled signal is determined from the comparison result.