摘要
为实现低频率段对热障涂层（Thermal barrier coating，TBC）的微波无损检测，利用同轴探头在0～17GHz工作频率范围内对热障涂层的厚度、孔隙率和金属基体表面的裂缝进行微波无损检测理论仿真，对检测中的参数敏感性进行研究，从而提高检测的灵敏度，防止漏检现象的产生。采用CST微波工作室对检测中同轴探头的尺寸和热障涂层的厚度等参数的检测敏感性进行理论计算。热障涂层厚度检测结果显示，同轴探头越小时检测灵敏度越高，并且对应的相位差零点处的工作频率越高；热障涂层孔隙率检测结果表明热障涂层的厚度越大时检测灵敏度越高；金属基体表面裂缝的检测结果表明扫描步长小于外导体内半径时可以防止漏检。由研究结果可知，利用合适尺寸的同轴探头可以实现在低频率段对热障涂层的微波无损检测。
In order to detect thermal barrier coating（TBC） using microwave non-destructive detection technique in the low frequency, the detection sensitivity, optimization of detection parameters is carried out detecting thickness and porosity of thermal barrier coating, and detecting crack of metal substrate, using coaxial probe which frequency is 0-17 GHz. The influence of the coaxial probe size, standoff distance, thickness and porosity of top coating（TC） is suited using CST-microwave studio. The results of detecting TC thickness show that the smaller the probe or the smaller the TC dielectric constant, the higher the frequency when phase difference equal to zero, and the smaller the standoff distance, the higher the detection sensitivity. The results of detecting TC porosity show that the higher the detection sensitivity, the larger the TC thickness. The results of detecting crack of metal substrate show that in order to prevent un-detection, the scanning length should be less than the radius of the probe. Therefore, it is feasible to detect TBC using microwave in low frequency, when coaxial was used a sensor.
出处
《机械工程学报》
EI
CAS
CSCD
北大核心
2014年第2期36-41,共6页
Journal of Mechanical Engineering
基金
国家自然科学基金资助项目(11072010)
