Open AccessLinear laser fast scanning thermography NDT for artificial disbond defects in thermal barrier coatings
Author(s) -
Zhanwei Liu,
Dacheng Jiao,
Weiqing Shi,
Huimin Xie
Publication year - 2017
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.25.031789
Subject(s) - thermography , thermal barrier coating , nondestructive testing , materials science , transient (computer programming) , composite material , thermal , optics , laser scanning , laser , coating , infrared , computer science , medicine , physics , meteorology , radiology , operating system
Interface disbond in thermal barrier coatings (TBCs) is one of the key issues that cause their premature failure. In general, blind hole defects are often used as substitutes in transient thermography. The linear laser fast scanning thermography (LLFST) method was developed in this study and combined with several post-processing algorithms to accurately detect blind hole defects in TBCs. Through numerical simulation and experimental verification, a unique thermal response characteristic of blind holes in the cooling phase, namely a distinct "tailing" phenomenon, was summarized and utilized to recognize small defects. Validation tests indicated that blind holes with diameters of 1, 2, and 3 mm and artificial disbonds with diameters of 2 and 3 mm in TBCs are detected with high efficiency.