Abstract:Copper and copper alloy are important metal materials in modern human life, which are widely used in communication electronics, rail transit, heat dissipation and refrigeration industries. Copper and copper alloy initial casting blanks often have internal defects such as holes, inclusions, porosity and cracks in industrial production, which seriously affect the subsequent processing and product quality. The traditional manual inspection method has low efficiency, poor accuracy, and can not judge the internal defects of billet. In this paper, the ultrasonic detection technology is applied to determine the internal cavity defects of copper alloy continuous casting plate. The response of ultrasonic detection to different types of cavity defects is studied by means of experiment and simulation, and the cavity defects are standardized and quantified by C-scan imaging technology. The results show that two kinds of prefabricated hole defects can be detected by adjusting the structure and parameters of ultrasonic testing equipment, and the optimal gain range of Φ1.2 mm flat hole defect and Φ0.8 mm straight hole defect is 53 DB-56 dB. Ultrasonic propagation in flat bottom holes with different diameters and side straight holes with different depths can be simulated by using multi-physics simulation software. Compared with the A-scan pulse reflection waveform after ultrasonic interaction with defects, the theoretical calculated value of ultrasonic propagation to the upper surface of defects differs by 3% and 6% respectively from experiment and simulation, which verifies the accuracy of simulation model.