Line-focusing ultrasonic probe used for Lamb wave velocity measurement on anisotropic materials

An anisotropic, ultrasonic probe technology, applied in the use of sound waves/ultrasonic waves/infrasonic waves for material analysis, measuring devices, and analysis of materials, etc., can solve the problem of low transducer frequency

CN102721750AActive Publication Date: 2012-10-10BEIJING UNIV OF TECH
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
Publication Date
2012-10-10

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Abstract

The invention relates to a line-focusing ultrasonic probe used for Lamb wave velocity measurement on anisotropic materials and belongs to the technical field of acoustic transducer. The role of the line-focusing ultrasonic probe is to convert pulse electric signals generated by an excitation source into vibration of piezoelectric thin films so as to generate ultrasonic signals, and meanwhile to receive reflection echoes of a tested sample and convert the ultrasonic signals into electric signals. By adopting a piezoelectric high molecular polymer as an exciting or receiving element, a joint, a metal spring, an upper metal shell, a lower metal shell, an insulating sleeve, a backing, insulation paste, an evaporation plating electrode and the like can generate ultrasonic signals with center frequency of 5MHz. No stretching operation is needed during the polarization process, and thus polarization difficulty is greatly reduced. The line-focusing ultrasonic probe provided by the invention has the advantages of long defocus distance, wide frequency band, high signal-to-noise ratio and the like, and can fully meet the need of experimental analysis.
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Description

technical field

[0001] The invention relates to an ultrasonic transducer used for the detection of leaky Lamb wave velocity of anisotropic materials, which belongs to the technical field of acoustic transducers, and its function is to convert the pulse electric signal generated by the excitation source into the vibration of the piezoelectric film so as to Generate ultrasonic signals, receive the reflected echo of the tested sample at the same time, and convert the ultrasonic signals into electrical signals. By analyzing the collected signals, the fluctuation characteristics of the measured material can be understood, and the mechanical properties of the material can be inverted. Background technique

[0002] The special transducer for non-destructive testing of material properties is the key to the entire testing system, and many scholars have done fruitful work in the development of focused transducers for material property testing. Lens-type ZnO, PZT or LiNbO for ultrasou...

Examples

Embodiment Construction

[0014] The specific implementation will be described in detail by taking a transducer with an opening angle of θ=90° and a focusing radius of R=10 mm as an example.

[0015] Such as figure 1 As shown, the transducer includes: joint 1, metal spring 2, upper metal shell 3A, lower metal shell 3B, insulating sleeve 4, backing 5, insulating glue 6, P (VDF-TrFE) piezoelectric film 7, Evaporation electrodes 8 and the like. The backing is used as the supporting structure and negative electrode of the P(VDF-TrFE) piezoelectric film 7, and it needs to be finished. The axis of the concave cylinder is in the same plane, and the radian and opening angle of the concave cylindrical surface determine the radian and opening angle of the P(VDF-TrFE) piezoelectric film. By finely grinding the concave cylindrical surface, the surface can reach the mirror level, the roughness Ra≤0.2μm. Prepare a polymer piezoelectric film with a thickness of 10-12 μm on the finished concave cylindrical surface....