Nondestructive Testing of Debonding Defects in Radar Absorbing Materials Based on Microwave Pulse Thermography Method

Radar absorbing materials (RAMs) are extensively utilized in radar stealth and satellite communications due to their excellent wave-absorption properties. However, the wave-absorbing properties of RAMs will be reduced due to debonding or peeling between the material and the substrate during use. Therefore, the efficient nondestructive testing (NDT) of defects in RAMs is a critical research topic. This article proposes an NDT technique for debonding defects in gradual waveguide microwave heating based on the microwave pulse thermography method (MWPTM). The system uses the combination of a magnetron and a gradual waveguide to heat the sample uniformly and an infrared thermal imager (IT imager) to detect the temperature change of the sample surface. By using multiple algorithms to analyze the detection data, the rapid and NDT of debonding defects can be achieved. The experimental results show that the system can accurately detect debonding defects in RAMs, with a minimum detection diameter–depth ratio of 1. This method can provide significant application value for rapid and NDT of RAMs.