航空发动机叶片在工作中要承受较高的离心负荷、气动负荷、高温和大气温差负荷以及振动的交变负荷, 同时还要受风沙、潮湿的浸蚀, 这些因素使叶片容易产生疲劳裂纹, 疲劳裂纹扩展会引起叶片断裂并影响发动机的安全。发动机叶片在发动机的服役期间需要定期进行无损检测, 但在叶片常规大修检测中经常需要对发动机进行拆卸、分解、检测和安装, 所需检测周期长, 费用高。通过超声波检测试验, 解决了低压一级转子原位超声检测叶片深根部位裂纹的技术难题, 为发动机叶片大修时的定期原位无损检测提供了方便、可靠的方法。

The aero-engine blade is often subjected with high centrifugal force, air dynamic force, thermal loading due to high temperature and temperature differences between surrounding, and vibration loading, and in addition it is also subjected with erosion by wind, sand and wet medium. All the above-mentioned factors shall cause the blade to develop fatigue cracks, which will threaten the safety of the engine. Therefore, during the service of the engine, the blade shall be under periodic maintenance and inspection for which the disassembling of the engine is needed and extra cost is required for this periodic inspection. The paper introduces an ultrasonic testing means for the non-destructive inspection of the cracks in deep blade root, providing an effective method for the in-situ testing of the engine blade.