Application of water immersion ultrasonic flaw detection in microstructure inspection of aluminum alloy ingots

Aluminum alloy casting structure is more prone to crack, undercasting, cold and other defects, these problems once appear will affect the structural stability and application reliability in different degrees. In order to identify these lack of accuracy problems in a timely manner, it is often necessary to add non-destructive testing in the entire process of conversion, and this link is also a more important link in the entire casting process. The use of ultrasonic flaw detection can effectively identify tissue defects, and can lock the location of defects, analyze the harm of defects, and provide reference for the treatment of defective materials. The traditional contact ultrasonic manual inspection has some disadvantages such as low efficiency, poor reliability and difficulty in judging the defect in the inspection of large-size ingot. Water immersion ultrasonic testing equipment was used to detect aluminum alloy ingot, and it was found that the overall noise ratio of the ingot exceeded $\mathbf{1 0 0 \%}$ from the ultrasonic C-scan spectrum. The results and application characteristics of the ultrasonic inspection were evaluated comprehensively, and the ingot was discarded, which provided a reference for the application of ultrasonic inspection in detecting the microstructure and defects of large size aluminum alloy.