超声红外热成像技术在航空发动机叶片裂纹的对比研究

Comparative Study of Using Ultrasonic Infrared Thermography for Detecting Aeroengine Blade Cracks

由于航空发动机叶片具有复杂的曲面结构,对服役过程中形成的微小裂纹检测带来了困难,文中采用超声红外热成像技术对航空发动机叶片裂纹实施检测,开展了超声红外热成像技术研究,搭建了超声红外热成像实验平台,并对实际服役过程中产生裂纹的航空发动机工作叶片进行检测。超声红外热成像结果与渗透检测、金相检测进行了对比;实验结果表明,对于该航空发动机工作叶片,超声红外热成像技术可以检测出2个裂纹缺陷、1个开口缺陷,采用渗透检测仅检测出1个裂纹缺陷,采用金相显微镜检测发现2个裂纹缺陷,宽度分别约为15μm、0.5μm,与超声红外热成像检测结果一致。对比结果表明超声红外热成像技术可以有效检测出航空发动机复杂曲面的叶片裂纹缺陷。

Owing to the complex curved surface structure of aeroengine blades,it is difficult to detect tiny cracks formed during servicing.In this study,ultrasonic infrared thermography technology was used to detect the blade cracks of an aero engine.Ultrasonic infrared thermal imaging technology was studied,and an experimental platform for ultrasonic infrared thermal imaging was built.In addition,the working blade of an aero engine with cracks arising from actual servicing was detected.The results of ultrasonic infrared thermography were compared with those of osmotic detection and metallographic detection.Experimental results show that in the working blade of the aero engine,ultrasonic infrared thermography technology detected two crack defects and one opening defect,whereas only one crack defect is detected by penetrant testing and two crack defects are detected by a metallographic microscope.The widths are approximately 15μm and 0.5 μm,respectively,which are consistent with the detection results of ultrasonic infrared thermography.The results show that ultrasonic infrared thermography technology can effectively detect crack defects in aeroengine blades with complex curved surfaces.