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

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.

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...

AI Technical Summary

Problems solved by technology

Although the piezoelectric properties of pure PVDF are very good, unidirectional or bidirectional stretching is required during the polarization process, which directly limits its ability to integrate with other components, and due to the need for stretching and polarization, PVDF films The thickness is limited to more than 10μm, so that the frequency of the fabricated transducer is relatively low

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