RU1783413C - Method and device for defectoscopy - Google Patents

Abstract

The invention relates to techniques for ultrasonic testing and cryoelectronics and can be used to control various workpieces and products, in particular cryogenic and superconducting devices. as well as in diagnostic systems AE and AI. The purpose of the invention to increase the sensitivity of the control method and the ability to visually inspect the surface of the controlled product is achieved by the location between the intermediate layer and the contact liquid of an additional active layer made of a conductor or semiconductor in an electric field at superconducting temperatures and a device containing a piezoelectric transducer, a prism, a fiber protector with the ability to inspect the surface of the controlled object simultaneously with ultrasound oic flaw detection using lenses of the crystallographic oprodukta, between which the tread is the active layer, reinforcing an acoustic signal in both forward and reverse directions. 5 ill. 1L C

Description

The invention relates to techniques for ultrasonic testing and cryoelectronics and can be used to control various installations and products, in particular, cryogenic and superconducting devices, as well as in piezoelectric filters of various electronic devices, for example, communication devices, in the diagnostic systems of AI and AE and etc.

The aim of the invention is to increase the sensitivity of the control method.

An additional object of the invention is the ability to visually inspect the surface of a controlled article while increasing the sensitivity of the control device.

A known method of control with the simultaneous use of light and ultrasound rays. A light beam is used to determine the quality of the contact when inspecting parts by ultrasonic contact method. If the transparent connector does not or does not fit in the control object, the light beam does not reach the photosensitive receiver, and the control system includes an alarm that there is no ultrasonic contact with the control object. Light radiation is not used to control the object, which is a disadvantage of the method.

As a prototype, a control method using at least two beams of a different type or frequency is used, simultaneously or sequentially focused on the object and only radiation sources are moved for scanning

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one type of radiation. A light beam can control an object both from the opposite, relative to the acoustic beam, and from the same side of the object, as well as in mutually perpendicular directions.

The method does not allow to control large objects such as oil pipes, due to the low sensitivity of the method, suitable only for small objects,

The most common piezoelectric transducers have significant disadvantages when converting oscillations into electrical signals, which can be compensated by using optical methods and A3 measuring instruments. however, for small A3 movements (10 -10 m), these movements are much shorter than the light wavelengths and the sensitivity of traditional interferometry does not provide informational and reliable control.

This goal can be achieved by increasing the sensitivity of the control method and using passive and active interferometers and coherent laser radiation, by increasing the sensitivity of the sensors.

The invention is as follows. A semiconductor placed in an electric field changes the sign of ultrasound absorption to negative. The same thing happens with a semiconductor when it is cooled to cryogenic temperatures, which accompany the appearance of superconductivity.

A similar phenomenon occurs with metals, i.e. with electricity conductors.

Under these conditions, the absorption of sound goes into its amplification.

The interaction of ultrasound with current carriers leads to the appearance of negative sound absorption, i.e. to amplify ultrasound, according to the laws of nonlinear physics.

To provide sound amplification in the acoustic path, an active layer is created in front of the piezoelectric transducer on the above principles.

The interaction of ultrasonic and electric fields leads to amplification of sound in the active layer.

By introducing an additional protector having a cryogenic temperature, cryostatting of the active layer is achieved, i.e. controlling its temperature to provide superconductivity (necessary to pre-amplify sound in the active layer) by stabilizing the superconducting temperature.

The implementation of the acoustic contact of the piezoelectric transducer with the object of control and preservation of the additional tread is carried out using cryogenic liquids.

In addition, the tread-cooling contact fluid plays the role of a liquid lens not only for ultrasound, but also for light energy (supplied through the same lens to a controlled object via optical fibers).

In this case, the interlayer of contact liquid acts as a collective of lenses and plays the role of a multi-lens for ultrasonic testing and for light and laser beams, together with a solid cryoproduct of an additional protector.

In order to avoid the white background of exposure to daylight and their interference when using optical fibers to inspect an object, the end surfaces of the optical fibers are coated with a layer of a film of oxytetitanium (or oxytetrasilane) equal to 1/4 of the total wavelength range of the visible spectrum.

If you change the polarity and magnitude of the electric field in the active layer, you get the opportunity to control its intensity, and also use the active layer as a shutter for acoustic rays and even as an acoustic modulator (like a Corr cell for optical rays), delaying the pulse sound when closed, superimposing on it the next passing acoustic pulse and opening the active layer after the imposition and modulation of the pulses.

The optical fibers used in the control method are used for double use: firstly, for visual inspection, and secondly, for laser excitation of acoustic waves.

Increasing the sensitivity of the method and amplifying the signal in the acoustic path allows one to get rid of the noise and interference of electronic equipment during amplification of the signal in the electronic path.

Amplification in the active layer and stabilization of the Curie temperature compensates for the absorption of ultrasound in the controlled objects and makes it possible to fabricate piezoceramics for a narrower temperature spectrum. Such stabilization of the Curie temperature is achieved due to the temperature constant of the cryoproducts used, .-.

Ray focusing i.e. control of the beams (light and ultrasound) is achieved using a lens of a liquid cryo-liquid lens and a solid cryoproduct (optional protector). The liquid lens additionally cryostats the solid cryoproduct (optional protector) and provides acoustic contact with the object due to wetting.

In FIG. 1 shows a sensor device with a piezoelectric transducer (PES) and optical fibers, an active layer of superconducting material, an additional protector (cryoprotectant) made of solid cryoproduct and an optical window in an opaque active layer (superconductor), FIG. 2 is also a device with optical waveguides (optical fibers) and a probe and an active layer of a transparent semiconductor in an electric field cooled by liquid cryoproducts, which are also contact liquids of ultrasonic control; in FIG. 3 and FIG. 4 is a diagram of a lens — an optical device made of solid and liquid optical elements with different refractive indices, which are simultaneously used for the optical range (IR radiation and visible light) and for ultrasound located on the inner or outer surface of the pipe, Fig. 5 is a diagram of the passage of audio signals and their amplification in the active layer in the forward and reverse directions.

The shown sensor devices shown in Figs. 1-4 consist of a prism - 1 with a piezoelectric transducer (PEP) -2, in which a supply pipe 3 of working cryofluid 4 (liquid nitrogen or liquid gel) is installed to provide acoustic contact between the sensor and the controlled product 5. In addition, in the prism 1 there are optical fibers with the direction of the rays which intersect at one point with the ultrasonic rays, one of the optical fibers illuminating and the other receiving. An active layer of a superconductor 7 with an optical transparent window 8 (which can be made in the form of a usual hole in a semiconductor) is installed on the path of propagation of light and ultrasound rays, the passage of electric current through which is carried out using electrodes 9, which are supplied for this voltage). To cryostat the active layer from superconductor 7, an additional protector 10 of solid cryogenic product (solid carbon dioxide or solid nitrogen) is used. If the additional tread 10 is made of solid carbon dioxide, then the liquid 4 is made of liquid nitrogen, if the additional tread 10 is made of solid nitrogen, then the liquid 4 is made of liquid argon (hydrogen, gels), etc.

The active layer can also be made of semiconductor 11 (Fig. 2), which is still transparent for light radiation (germanium for infrared radiation). The ends of the optical fibers 6 (Fig. 1 and Fig. 2) or a transparent active tread 11 are coated to protect (from exposure) from the white background in the image a tetraoxytitanium (tetraoxysilane) film 1/4 thick of the backlight background wavelength.

In FIG. 3 shows the installation of a sensor with an active layer on a controlled pipe from the inside, and in FIG. 4 - outside the pipe, and where the cryo-fluid has the shape of a lens (convex or concave), which is an optical element at the same time for optical radiation and ultrasound. Optical system for optical fibers (visible light or infrared radiation) and ultrasonic control, because materials with different refractive indices work as optical elements, i.e. there is a collective of optical elements or a lens, Where the lens is one liquid T sTs with an expectation of 4, and the remaining solid elements with different refractive indices that affect the beams of ultrasound, visible light, infrared radiation (IR), control (the latter) in this way. The spherical surface of the liquid lens forms the surface of the controlled pipe.

In FIG. Figure 5 shows the scheme of amplification of ultrasound rays during flaw detection, where the ultrasound rays emitted by the piezoelectric transducer 2 in the forward direction 14 pass through the prism 1 from the fluoroplastic and enter the active layer 12, amplified and directed towards the defect 13, part of the rays pass the defect , a part is reflected from it and passes in the opposite direction 15, enters the active layer 12, amplifies in it, through a prism 1, it enters a combined type piezoelectric transducer 2. Further, the signal is supplied in the traditional way to conventional serial flaw detector equipment, for example, UD2-12 (ultrasonic flaw detector).

Liquid gas is supplied to the tube 3 from a liquid gas cylinder, for example prop-butane liquid nitrogen, argon, liquid carbon dioxide, helium, hydrogen.

Solid nitrogen can be cooled with liquid nitrogen and solid nitrogen is retained by evaporation of the latter.

The method is implemented in the operation of devices (sensors) as follows.

A cryofluid 4 is supplied through the tube 3 until the gap between the Sensor and the product 5 is completely filled.

A solid cryogenic tablet 10 is installed in the sensor housing, which, together with the sensor, is stored in a cryostat for operation.

An additional protector 10, together with a -cri-liquid 4 cools the active layer 7 or 11 (Fig. 1 and Fig. 2).

The active layer 7 or 11 is placed in an electric field and a superconducting current flows through it using electric wires 9.

The combined probe in the echo-pulse mode works through an additional protector (cryoprotectant) 10 and an active layer 7 (or 11) both in the reception mode and in the radiation mode, in this case, the optical fibers are only for visual inspection by eyes or optically - electronic devices.

Instead of a coupled probe, a separately coupled converter can be used as converter 2, which can be (like all serial probes) both an inclined converter and a direct converter. Serial probes receive a signal in the same angle at which they radiate into the object.

When ultrasound is emitted by the piezoelectric transducer 2 through a prism 1, an active layer 7 (or 11), an additional protector 10, a liquid cryo-liquid lens 4 in a controlled article, the ultrasound is amplified in the active layer 7 (or 11). Ultrasound is reversed.

Ultrasound enhancements are carried out both forward and backward (see Fig. 5) through the active layer.

Simultaneously with ultrasonic flaw detection, the surface of the product under inspection 5 is inspected through optical fibers b, one of which is the illuminating one and the other receiving one.

If the active layer is transparent for the emission of optical fibers 6, like germanium in the tread 11, then the light is transmitted directly through it (infrared radiation), if the active layer is transparent for light radiation, like superconductor 7, then transparent windows 8 are made in it. (or holes) to inspect the surface of the product 5. With this combined control of pipes, cryo-liquid 4 acts as a liquid lens, i.e. focusing element of a complex lens, consisting of many lenses, elements and materials with different refractive indices (see Fig. 3 and Fig. 4).

Sound amplification occurs in the active layer 12 to the defect 13, both in the prime 14 and in the reverse 15 directions, relative to the transducer 2 (see Fig. 5). This amplification is based on the physical effect of negative absorption of ultrasound passing through a semiconductor or superconductor placed in an electric field, i.e. sound amplification occurs, and although part of the ultrasound energy passes by the defect and only a small part falls on the defect, but due to this amplification (negative absorption), this energy nevertheless reaches the piezoelectric transducer previously amplified in the backing protector, and, due to the cooling of the product zone with cryofluids providing acoustic contact reduce attenuation in the test object itself.

Practical flaw detection is carried out without changing the existing methods for detecting defects, for example, by ECHO-pulse method on a UD 2-12 flaw detector using a strobe pulse, on which a probe and bottom pulse are first recorded and then the necessary measurements are made.

A voltage of 10 V is applied to the active layer from germanium and cooled with a contact liquid, for example, a mixture of liquid hydrogen or gel (5-15) K °. A voltage of 10 V is applied to the active layer of a superconductor (alloy, for example, niobium-zirconium, niobium-titanium, niobium-tin) and cooled with the same composition of liquid hydrogen-gel.

The acoustic energy amplified in the active layer and converted by the probe into electrical impulses (after processing in UD2-12) is displayed on a CRT screen.

Using optical waveguides, an external object is inspected, or powerful laser pulses generate acoustic vibrations in the object, which are then picked up by the probe.

The sensitivity of this method depends on the absorption of sound and the sensitivity of the acoustic sensors. In both cases, these factors are taken into account with a positive effect. Absorption, due to cooling by the cryogenic contact liquid, decreases, and the sensitivity of the sensors increases due to the operation of the active layer.

The recording of the results of optical control is carried out using cinema-photo-video equipment and other devices, as well as video sensors. The method and sensors are also applicable to diagnostic systems, for example using AE and AI.

Claims (5)

1. The method of flaw detection, which consists in the fact that optical and acoustic are introduced into a controlled object simultaneously or sequentially through a solid intermediate layer and contact liquid radiation, receive optical signals reflected from surface defects and acoustic signals from internal defects, measure their parameters and determine the quality of the object, which, in order to increase sensitivity, has an additional layer between the intermediate layer and the contact liquid active layer. 2. The method according to claim 1, characterized in that the additional active layer is made of a conductor or semiconductor and is affected by an electric field of a predetermined value. 3. A method according to claim 1, characterized in that the additional layer is made of a conductor or semiconductor and cooled to a temperature ensuring its superconductivity. 4. The method according to claim 3, characterized in that as the contact fluid used cryoproduct in the liquid phase. 5. Defectoscopy device comprising a piezoelectric transducer, a prism, a light guide, a tread, characterized in that, for the purpose of visual inspection of the surface of the controlled product and increasing sensitivity, it is equipped with an additional optical fiber and an active layer installed between the prism and the protector, a lens from the cryoproduct in the liquid phase, located between the protector and the surface of the test object in a special shell, the protector is made from the cryoproduct in the solid phase. / b FIG. 2 .. Reg.Z. Fig / 3 /5 / .5;