Study on the detection ability of laser ultrasonic SAFT technology for lead internal defects

Lead has good corrosion resistance and sealing property, which is often used in cable lead sealing process and various processes. In the production process, there may be small defects in the lead products, which may affect the quality of the products. Therefore, it is of great economic significance to inspect them to ensure their reliability. Due to the variety of lead products, the use of traditional ultrasonic detection is limited, and laser ultrasound has the ability to detect all kinds of surface samples. However, when the inner defect size of lead products is submillimeter or smaller, the echo signal-to-noise ratio(SNR) is low, so the traditional laser ultrasonic technology is difficult to locate the defects. In this paper, the synthetic aperture focusing (SAFT) technology is applied to the laser ultrasonic detection of lead internal defects. The minimum defect identification ability and resolution ability of laser ultrasonic combined with SAFT are studied, which provides reference for practical application.