RU1810814C - Method of ultrasonic echo testing for continuity of joint of two materials with different wave resistances - Google Patents

Abstract

The invention relates to non-destructive testing and can be used to determine the quality of structures and products in mechanical engineering, shipbuilding, aircraft industry and construction industry. The purpose of the invention is to increase the accuracy of determining the magnitude of the defect when controlling the connection on the material side with a lower specific wave impedance - is achieved by using as a zone of movement of the transducer a zone within which the amplitude of the echo signal changes twice: first from the maximum value to zero, and then from zero to a maximum value corresponding to the amplitude of the echo from the defect-free boundary of the joint. 1 s.p. file, 2 ill. ate

Description

The invention relates to non-destructive testing, and in particular, to methods of ultrasonic echo-checking of the continuity of the joining of materials and can be used to determine the quality of structures and products in mechanical engineering, shipbuilding, aviation industry and construction industry.

The purpose of the invention is to increase the accuracy of determining the magnitude of a defect when controlling the connection on the material side with a lower impedance.

In FIG. Figure 1 shows a graph of the amplitude A of the echo signal versus the position of the transducer, where b and b are the true and measured values of the defect, respectively; Fig.2 is a control circuit, where 1 and 2 are the connection materials of the monitored product, 3 is a defect, 4 is an ultrasonic transducer, in a position where the amplitude of the echo signal A has a maximum value, the ultrasonic transducer is in positions 5 and 6; when the amplitude of the echo signal is due to the reflection of ultrasonic vibrations from the defect-free boundary of the joint (extreme positions by which the magnitude of the defect is determined).

The method is carried out as follows.

The ultrasonic transducer is placed on the material side 2 with a lower specific wave impedance (coating), ultrasonic vibrations are emitted into it (the propagation of ultrasonic vibrations is schematically shown by arrows), the vibrations reflected from the connection boundary are received, and scanned

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the controlled surface by the transducer 4 and fix the defect by increasing the amplitude of the reflected signal. The transducer 4 is fixed in the position where the amplitude of the echo signal has a maximum value (see curve 7) and the magnitude of the defect b is determined by the length of the movement zone L1 of the transducer, within which the amplitude of the echo signal when moving in opposite directions from the position of the transducer 4 (the directions of movement are shown by arrows) first decreases to zero, and then increases to a value equal to the amplitude of the echo signal from the defect-free boundary of the connection. These positions are shown in Fig. 1 by 5 and 6. Thus, the interval of movement of the transducer from 5 to position 6 is b and corresponds to the true value of the defect b.

Correspondence of the measured value to the true value of the defect allows us to conclude that the proposed control method provides an increase in the accuracy of determining the value of the defect.

It should be noted that in the proposed Method it is considered that the near zones of the transducer and the defect are commensurate with the coating thickness (material 2) and there is no discrepancy between ultrasonic vibrations. This case is most often implemented in practice (including the implementation of the prototype).

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The proposed method of ultrasonic echo-control of the continuity of the connection is implemented using known means: serial echo-flaw detectors such as UD2-12, UD2-16, UD-23UM and their transducers.

Claims (1)

Formula and zobret e.n and The method of ultrasonic echo control of the continuity of the connection of two materials with different wave impedances, namely, that the surface of the connection is scanned by an ultrasonic transducer, the amplitude of the echo signal from the interface is measured, the amplitude is judged by the presence of a defect, and the length of the zone the displacement of the transducer, within which the signal from the detected defect is perceived, judges the size of the defect, characterized in that, in order to increase the accuracy of determining the magnitude of the defect at For the connection on the material side with a lower specific wave impedance, the zone within which the amplitude of the echo signal changes twice: first from the maximum value to zero, and then from zero to the maximum value corresponding to the amplitude of the echo signal, is used as the transducer movement zone from the defect-free boundary of the joint. Figure 1