Eddy Current Thermography with Adaptive Carrier Algorithm for Non-destructive Testing of Debonding Defects in Thermal Barrier Coatings
Eddy Current Thermography with Adaptive Carrier Algorithm for Non-destructive Testing of Debonding Defects in Thermal Barrier Coatings
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DOI：
10.1007/s10921-018-0483-3
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发表时间：
2018-04
影响因子：
2.8
通讯作者：
Wenying Zhu;Zhanwei Liu;Dacheng Jiao;H. Xie
中科院分区：
文献类型：
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作者：
Wenying Zhu;Zhanwei Liu;Dacheng Jiao;H. Xie
界面缺陷会导致热障涂层过早失效。提出了一种在加热阶段传输模式下的涡流热像(ECT)方法，用于检测热障涂层样品中的人工剥离缺陷。当使用ECT时，由于几何加热效应、集肤效应、边缘效应和异常发射率的影响，试件表面的温度分布不均匀。其中，表面发射率的影响最小，因为在对热图像进行处理之前，会先减去背景噪声。不均匀的温度分布屏蔽了缺陷的弱热响应特性，干扰了缺陷的识别。为了解决这一问题，建立了自适应载波算法作为后处理算法。通过对含2 mm人工脱粘缺陷和0.5 mm盲孔缺陷的热障涂层试件进行模拟和验证试验，验证了所提方法的可行性和有效性。
Interfacial defects can cause the premature failure of thermal barrier coatings (TBCs). An Eddy current thermography (ECT) method under the transmission mode in the heating phase is developed in this study to detect the artificial debonding defects in TBCs samples. When ECT is used, the temperature distribution of specimen surface is uneven on account of geometric heating effect, skin effect, edge effect and abnormal emissivity. Among them, the influence of the surface emissivity is the smallest, because the background noise is subtracted before the thermal images are processed. The uneven temperature distribution shields the weak thermal response characteristics of the defects and interferes with the identification of the defects. Adaptive carrier algorithms are established as post-processing algorithms to resolve this problem. The feasibility and validity of the developed methods are verified by simulation and validation tests using TBCs samples with a 2 mm artificial debonding defect and a 0.5 mm blind-hole defect.