TY - JOUR
TI - Infrared thermal wave detection of interfacial debonding defects of thermal barrier coatings based on non-linear frequency modulation
AU - Tang Qing-Ju
AU - Zhang Tao
AU - Gu Zhuo-Yan
AU - Bu Chi-Wu
JN - Thermal Science
PY - 2023
VL - 27
IS - 1
SP - 705
EP - 711
PT - Article
AB - In order to improve the reliability of detecting the debonding defects at the  interface of thermal barrier coatings (TBC), a non-linear frequency  modulated (NLFM) infrared thermal wave detection method is proposed. A NLFM  infrared thermal wave detection system is built, and zirconia TBC specimens  are prepared and tested. The effects of defect diameter, excitation power,  initial frequency and termination frequency on the defect detection effect  are analyzed. Three algorithms such as principal component analysis (PCA)  are used to process the image sequence, and the signal-to-noise ratio (SNR)  of each sequence processing algorithm is calculated and compared. The  results show that the larger the diameter of the defect, the easier it is to  be detected, and the appropriate adjustment of the excitation power or the  reduction of the initial and termination frequencies is beneficial to the  detection of defects. Compared with the other two algorithms, the PCA method  is more effective for image sequence processing. It offers a reference for  detecting debonding flaws at the TBC interface.