Ultrasonic C-scan Detection of Aluminum Honeycomb

Plate Brazing Joint

Aluminum alloy honeycomb panels are mainly formed by bonding and brazing. Among them, brazed aluminum alloy honeycomb panels have higher connection strength, so they have become the main development direction. At present, the conventional destructive inspection method of brazed joints can only be sampled, which is difficult to completely reflect the quality of the actual welded structure. Therefore, the non-destructive inspection of aluminum alloy brazed honeycomb panels has important engineering significance.

Ultrasonic testing technology has received extensive attention in the field of non-destructive testing due to its advantages of convenience, efficiency and safety [2-3], and it has been relatively mature in the evaluation of welding quality of thin-plate structures such as resistance spot welding and laser welds [2-3]. 4-5]. In this paper, the effective connection area of ​​brazed joints, a key index for evaluating brazing quality, is studied by means of precise positioning of ultrasonic C-scanning detection, in order to achieve quantitative non-destructive testing and evaluation of brazing connection status of aluminum alloy honeycomb panels. The quality control of brazing forming of aluminum alloy honeycomb panels has important engineering significance.

The test material is a brazed aluminum alloy honeycomb panel, the upper and lower skins and the middle honeycomb core are both AA3003 aluminum alloy; the skin and the honeycomb structure are connected by brazing method, the brazing material is AA4343 aluminum alloy, and the thickness of the upper and lower skins is 1 mm, the honeycomb core thickness and height are 0.2 mm and 13 mm, respectively.

Detection equipment and method

Automatic ultrasonic C-scan inspection system for brazed joints of aluminum alloy honeycomb panels. The system consists of a portable industrial computer, a full-featured ultrasound card, an X-Y mechanical motion mechanism and a focused ultrasound probe with a center frequency of 15 MHz. The automatic ultrasonic inspection system can realize the step-by-step precise positioning ultrasonic C-scan inspection of aluminum alloy honeycomb panels. During the ultrasonic inspection process, at each step-scan node, an A-scan signal is obtained and automatically stored in the computer for easy data recording and analysis. The scan step size is 0.108 mm. After scanning, the obtained ultrasonic C-scan detection data matrix is ​​200×200.