CN102778511A

CN102778511A - Ultrasonic guided wave transducer for flat nondestructive testing

Info

Publication number: CN102778511A
Application number: CN2011101246096A
Authority: CN
Inventors: 王维斌; 陈健峰; 艾慕阳; 佟文强; 刘广文; 赵丑民; 冯展军; 王禹钦; 刘哲; 任重
Original assignee: Petrochina Co Ltd
Current assignee: Petrochina Co Ltd
Priority date: 2011-05-13
Filing date: 2011-05-13
Publication date: 2012-11-14

Abstract

The invention discloses an ultrasonic guided wave transducer for flat-plate nondestructive testing, and relates to the technical field of ultrasonic measurement and pipeline systems. The piezoelectric ceramic is composed of a piezoelectric wafer (4), a wedge block (3) with special geometric parameters, a front liner (1) and a shell; a piezoelectric wafer (4) is arranged on one side surface of the top corner of the wedge block (3), a front lining (1) is adhered to the other side surface of the top corner, saw teeth (2) are uniformly distributed at the position close to the top corner, and a shell is covered outside the wedge block (3); the wedge block (3) is made of copper, the top angle is a right angle, the angle of one bottom angle is 37-50 degrees, and the other bottom angle is the rest angle; the sawteeth (2) are uniformly distributed on the wedge block (3) near the top corner. The invention has simple structure, economy and applicability, long detection distance and high resolution.

Description

A kind of ultrasonic guided wave energy exchange device of dull and stereotyped Non-Destructive Testing

Technical field

The present invention is a kind of ultrasonic guided wave energy exchange device that is used for the dull and stereotyped Non-Destructive Testing of planar plate members Ultrasonic NDT, relates to hyperacoustic measurement and piping system technical field.

Background technology

Compare with traditional ultrasonic technology, utilize the propagation characteristic of supersonic guide-wave in solid dielectric to come the new technology of test material and structure to have sensitiveer, more economical characteristics.Supersonic guide-wave has the character of frequency dispersion, and phase velocity, group velocity and the decay that need solve guided wave in theory could be instructed actual detection work so better with the relation of change of frequency.Yet the mechanism of transmission of supersonic guide-wave still awaits further research could instruct engineering practice better.

The supersonic guide-wave forms of sensor has piezoelectricity wedge transducer, EMAT, comb transducer, interdigital transducer, magnetostrictive transducer, laser-ultrasound transducer etc. in the plate of using always in the engineering.Above transducer respectively has characteristics; But when the time with a sheet material supersonic guide-wave Non-Destructive Testing; Piezoelectricity wedge wave guide energy converter is high at projectile energy, detect distance, resolving power is big, small investment, aspect such as good in economic efficiency are occupied certain advantage; Cost performance is higher in the common engineering detection is used, and the also increase thereupon of the resolution of other transducer defective when detecting the distance increase.

CN201177617Y discloses a kind of ultrasonic guided wave energy exchange device of Non-Destructive Testing in (on January 7th, 2009), and it is made up of piezoelectric chip, the voussoir with special geometric parameter, backing, shell.But it can not absorb acoustic energy better, can not adapt to the Distance Test of different-thickness sheet material well.

Summary of the invention

The objective of the invention is to invent a kind of simple in structure, economic and practical, ultrasonic guided wave energy exchange device of detecting distance, dull and stereotyped Non-Destructive Testing that resolution is high.

The present invention is a kind of piezoelectricity wedge wave guide energy converter that is used for dull and stereotyped supersonic guide-wave Non-Destructive Testing, with a sheet material Non-Destructive Testing.

The present invention is based on the result that all combined factors such as the physical dimension, detection range of thickness, sound wave oblique incidence, the piezoelectric crystal of frequency, wavelength, the sheet material of sound wave are considered.

The structure of this ultrasonic guided wave energy exchange device is seen Fig. 1-Fig. 3, and is the same with prior art, and it is made up of piezoelectric chip 4, the voussoir 3 with special geometric parameter, preceding lining 1, shell.Piezoelectric chip 4 is installed in a side at voussoir 3 drift angles, and the side in addition of drift angle is stained with preceding lining 1, and evenly is being placed with sawtooth 2 near the drift angle place, and voussoir 3 is covered with shell.

It is characterized in that:

Voussoir 3 is a copper material, and drift angle is the right angle, and wherein the angle at a base angle is 37～50 °, and another base angle is its complementary angle;

The sawtooth groove depth 1～2mm of serrated face, pitch 1～3mm, 50～70 ° at bottom land angle;

Wherein:

Suitably pressurize under 100～120 ℃ temperature with epoxy resin between piezoelectric chip 4 and the voussoir 3 and toast bonding getting final product;

Preceding lining 1 forms for the tungsten powder sintering;

Voussoir 3 adopts interference fit with shell, only need during installation it is press-fited get final product, when carrying out in the use afterwards safeguarding on the structure only need with its separate just can, guaranteed to detect the convenience of use.

Through the different excitation pulse frequency of conversion, can excite the ultrasound wave of different wave length, be applicable to the remote detection of different-thickness sheet material.

Succinct on explaining; The present invention only is illustrated the inner structure of ultrasonic guided wave energy exchange device; Concrete transducer enclosure, wafer lead-in wire etc. only need to get final product with reference to the technology that designs and produces of general transducer, can carry out confirming flexibly according to the process conditions at scene.

This ultrasonic guided wave energy exchange utensil has following characteristics:

(1) simple in structure;

(2) the probe working service is convenient;

(3) be applicable to long detection apart from sheet material.

Description of drawings

Fig. 1 wave guide energy converter structure front elevation

Fig. 2 wave guide energy converter structure side view

Fig. 3 PZT wafer synoptic diagram

Fig. 4 wave guide energy converter structure excitating performance test waveform figure

Fig. 5 wave guide energy converter detectability test waveform figure

Fig. 6 wave guide energy converter detectability test waveform figure

Wherein serve as a contrast the 2-sawtooth before the 1-

3-voussoir 4-piezoelectric chip

Embodiment

Embodiment. this routine structure is seen Fig. 1-Fig. 3, and it is made up of piezoelectric chip 4, the voussoir 3 with special geometric parameter, preceding lining 1, shell.Piezoelectric chip 4 is installed in a side at voussoir 3 drift angles, and the side in addition of drift angle is stained with preceding lining 1, and evenly is being placed with sawtooth 2 near the drift angle place, and voussoir 3 is covered with shell.

Wherein:

Copper voussoir 3 materials are copper, and the voussoir drift angle is the right angle, and another base angle is 43 degree, the dark 1mm of copper voussoir sawtooth, and pitch is 2mm;

The length of piezoelectric chip 4 is 26mm, and width is 20mm, and thickness is 1mm;

Suitably pressurize under 120 ℃ temperature with epoxy resin between piezoelectric chip 4 and the copper voussoir 3 and toast bonding;

Preceding lining 1 is the tungsten powder sintering;

Voussoir 3 adopts interference fit with shell.

In order further to compress the ripple bag of echo, consider that wave guide energy converter carries out structure Design and improves, reduce the echo interference in the probe copper voussoir through adding suitable backing; Beginning ripple when being illustrated in figure 4 as voussoir and not adding backing has 4 tangible peak values; Shown in Figure 5 for the beginning ripple of voussoir when not adding backing has only 1 unconspicuous peak value, visible, through change, control kinds of processes parameter; Reach the echo that reduces in the probe and disturbed, reached the purpose of further compression and back wave-wave bag.For detection signal, flaw indication ripple bag has obtained compression, though amplitude descends to some extent under the bigger situation of surplus sensitivity, this does not influence the detection effect, and is as shown in Figure 6.

Shown in Figure 6 for wave guide energy converter to the detectability in hole: be that the detection of echoes in 20mm hole is 4～5 times to equivalent diameter on the steel plate thick at 10mm, that 3m is long, distance is equivalent to 12000mm.

Test shows: the wave guide energy converter that the present invention designed, on the thick steel plate of 10mm, equivalent diameter being detected distance for the 20mm hole is 12000mm, can satisfy most demands of sheet material Ultrasonic NDT.

This example is through test, and is simple in structure, and the probe working service is convenient, is applicable to long detection apart from sheet material, is applicable to the remote detection of different-thickness sheet material.

Claims

1. the ultrasonic guided wave energy exchange device of a dull and stereotyped Non-Destructive Testing, it by piezoelectric chip (4), have the voussoir (3) of special geometric parameter, preceding lining (1), shell and form; Piezoelectric chip (4) is installed in a side at voussoir (3) drift angle, and the side in addition of drift angle is stained with preceding lining (1), and evenly is being placed with sawtooth (2) near the drift angle place, and voussoir (3) is covered with shell; It is characterized in that voussoir (3) is a copper material, drift angle is the right angle, and wherein the angle at a base angle is 37～50 °, and another base angle is its complementary angle; Evenly be placed with sawtooth (2) at voussoir (3) near the drift angle place.

2. the ultrasonic guided wave energy exchange device of a kind of dull and stereotyped Non-Destructive Testing according to claim 1 is characterized in that the sawtooth groove depth 1～2mm of said sawtooth (2), pitch 1～3mm, 50～70 ° at bottom land angle.