Research On Ultrasonic Nondestructive Testing Of Interface Bonding State Of Aluminum Matrix Composites

Aluminum based materials are now used in important parts of aerospace and military industry.The bonding structure of aluminum based materials may have defects and damage in the process of manufacturing and using.The testing of bonding quality is mainly divided into the testing of interface bonding state and the testing of bonding strength.The laser spallation method and other methods need to be based on the measurement of interface bonding state.In this paper,the ultrasonic nondestructive testing method is mainly used to detect the interface bonding state of aluminum based materials The detection was carried out.In this paper,DP460 epoxy resin adhesive and aluminum substrate,glass,polytetrafluoroethylene and other materials were used to prepare different aluminum matrix bonding experimental samples and different interface bonding states of the same aluminum matrix sample by hot pressing.The water immersion ultrasonic A-scan experimental platform was established,and the error of the experimental platform was calibrated according to the sound velocity of water Acoustic information is obtained by ultrasonic testing.Then the interface bonding state of aluminum based materials was detected by water immersion ultrasonic A-scan method and water immersion ultrasonic C-scan method,and the received signal was analyzed.The results show that: using two methods of changing sound path based on transducer moving and changing sound path based on reflecting bottom surface to calibrate and measure the sound speed of water,the measurement error of the system is 0.13%;using changing sound path based on reflecting interface to measure aluminum substrate,the sound speed of aluminum substrate is(6375.97)in 90% confidence interval 97m/s;using Comsol software to simulate the ultrasonic testing of aluminum based materials,through the simulation,it can be concluded that the 15 MHz ultrasonic transducer probe is conducive to the detection of the interface bonding state of aluminum based materials.At the same time,with the increase of the debonding defect size on the interface of aluminum based materials,the ultrasonic echo signal energy will gradually increase and finally tend to be stable Phenomenon.The aluminum based material bonded by DP460 meets the use standard,and the stable and durable bonding interface without bubble impurities can be obtained by this manufacturing method.In the ultrasonic water immersion A-scan experiment of aluminum based material,the sound velocity of each medium of aluminum based material has a good corresponding relationship with the different interface bonding state of aluminum based material,and the qualitative judgment of the interface bonding state of aluminum based material is good or not The results show that the fracture can be obtained by transit time method from the acoustic time information in time domain analysis,and the debonding degree on the interface of aluminum based materials has a good corresponding relationship with the amplitude information of ultrasonic reflection signal.The ultrasonic water immersion A-scan measurement method can be used to evaluate the interface bonding state of aluminum based materials.For the ultrasonic water immersion C-scan imaging experiment,based on the reflection waveform obtained from A-scan experiment,the color difference on the scanning image obtained by scanning different interface depths of aluminum based materials can directly characterize the interface bonding state of aluminum based materials.Different testing methods have their own advantages and disadvantages.In general,ultrasonic nondestructive testing can effectively measure the interface bonding state of aluminum based materials.