针对复合材料的无损检测问题, 探讨了一种基于穿透式异侧检测模式的空气耦合式超声波检测技术, 阐述了该技术的基本原理。参照传统的液浸式超声波检测技术, 以航空工业中重要的γ-TiAl基合金为研究对象, 对检测过程中信号的衰减与损耗进行了详细的理论分析与数值计算。结果表明, 超声波在介质交界面处的反射损耗和在空气中的传输衰减是目前空气耦合式超声检测技术应用遇到的主要难题, 而研制新型超声波换能器是解决问题的关键。

Aiming at the problem of non-destructive testing in composite materials, the air-coupled ultrasonic testing based on the penetrative opposite side detection mode was discussed. The principle of the technique was described. Compared with the traditional water-coupled ultrasonic testing, the aviation important composite material γ-TiAl alloys were researched, the detection signal losses and attenuation of the technique were analyzed and calculated. It was concluded that the reflection loss at the medium interface and the transmission attenuation of ultrasonic in air was the main difficulties for the application of air-coupled ultrasonic testing technique. However, the key problem was the development of new ultrasonic transducer.