Enhancement characteristics of laser ultrasonic basin-type insulator based on carbon nanocomposites

Abstract

Laser ultrasonic technology has been widely used in the field of NDT due to its advantages of non-contact and high resolution. The sensitivity of laser ultrasonic detection signal is not only related to laser excitation parameters, but also to the thermal absorption of the target. Therefore, once the measured target is determined, the sensitivity of laser ultrasonic detection based on thermoelastic effect is limited by the damage threshold of the measured target. In order to improve the sensitivity of the detection signal under the damage threshold, it is a good choice to add a layer of enhanced medium with high photoacoustic conversion efficiency on the surface of the laser target material. Based on this, a method based on CB(carbon black)-PDMS composite film was proposed to enhance the sensitivity of detection signal.