基于钆掺杂法的空心涡轮叶片残芯冷中子照相检测

Cold neutron radiography testing of residual core in hollow turbine blade based on gadolinium doping method

针对航空发动机DD5单晶高温合金空心叶片,采用钆掺杂法设计制作了阶梯状模拟试样和叶片对比试样,使用冷中子源和单面乳化胶片的成像方式,研究了Gd_(2)O_(3)示踪剂含量为3%时残芯的检测灵敏度,分析了灵敏度、透照厚度和残芯厚度之间的定量关系以及叶片结构对检测结果的影响。试验结果表明,采用单面乳化胶片的冷中子照相检测的空间分辨力达到50μm;随着透照厚度的减小及残芯厚度的增加,残芯检测灵敏度逐渐增加,且复杂曲率的叶片结构将一定程度地降低检测灵敏度。该结果为空心涡轮叶片的实际检测提供了参考,同时证明了冷中子照相检测具有良好的适用性,可实现残芯的高灵敏度检测。

For DD5 single crystal superalloy blade of the Aeroengine,the stepped reference sample and blade reference samples were designed and prepared by gadolinium doping method.Using cold neutron source and imaging method of single-emulsion industry film,the detection sensitivity of residual core with Gd_(2)O_(3)tracer content of 3%was studied.The quantitative relation among sensitivity,transmission thickness and residual core thickness,as well as the influence of blade structure on detection results were analyzed.The results show that the spatial resolution of the combination of cold neutron source and single-emulsion film is up to 50μm.With the decrease of transmission thickness and the increase of residual core thickness,the detection sensitivity of residual core increases gradually.The results provide a reference for the practical application of hollow turbine blade,proves that the cold neutron photography testing has good applicability,which can achieve the high detection sensitivity of residual core.