Study on Ultrasonic Testing of Interface Bonding State of Aluminum Matrix Composites

The ultrasonic reflection characteristics of various interface bonding states of aluminum matrix bonding composites bonded with epoxy resin adhesive were investigated. The simulation of the ultrasonic testing is developed, and by analyzing the simulation results, the ultrasonic transducer with a frequency of 15 MHz is effective in detecting the interface bonding state of aluminum matrix composites with an epoxy resin bonding layer of 0.3 mm thick. With the increase in the size of debonding defects on the bonding interface, the energy of the echo ultrasonic signal shows a positive correlation-increasing trend. The water immersion ultrasonic A-scan testing method was applied to conduct testing experiments, and the results show the change of the bonding state of the bonding layer had a relationship with the amplitude of the reflected waves between the lower surface of the first layer of bonding material and the upper surface of the aluminum substrate. The interface bonding state of the aluminum matrix composite was also visualized by immersion ultrasonic C-scan method. The color difference of the scanned image was analyzed and provides effective characteristics for detecting the interface bonding state of the aluminum matrix composite. This study provides a basis for testing the interface bonding strength of aluminum matrix and other composite materials.