针对飞机金属结构在服役过程中的裂纹实时监测需求,提出一种Ti/TiN导电薄膜与电位监测原理相结合的结构裂纹监测研究方案.首先,通过真空离子镀膜技术在结构易于出现裂纹的部位制备了Ti/TiN薄膜传感器.然后,进行了传感器膜层与2A12-T4铝合金基体的损伤一致性验证.结果表明,传感器与基体具有良好的损伤一致性.最后,进行了两组基于Ti/TiN薄膜传感器的裂纹监测试验,主要研究结构裂纹与传感器电位之间的相互关系,并对两组电位监测结果进行对比.结果表明,通过分析Ti/TiN薄膜传感器电位的变化可以实现对2A12-T4铝合金结构裂纹萌生和扩展进行实时监测,两组试验的电位监测结果具有良好的重复性.
According to the real-time crack monitoring demand of aircraft metallic structures during their service, a structure crack monitoring method is presented based on the Ti/TiN conductive film and the electrical potential monitoring principle. First, a Ti/TiN film sensor is deposited on a hot spot of a structural surface by vacuum ion plating. Then, the damage consis- tency of the sensor film with the 2A12-T4 aluminum alloy substrate is verified by a fatigue test with excellent damage consis- tency. Finally, two groups of crack monitoring tests are carried out with Ti/TiN film sensors. The relationships between the electrical potential values of the sensors and the structural cracks are studied, and the two groups of monitoring results are compared, which shows that monitoring the structural crack origination and propagation of 2A|2-T4 aluminum alloy in real- time can be achieved through analyzing the changes of the electrical potential values of the Ti/TiN film sensors, and the re- peatability of the monitoring tests results is satisfactory.