TITLE

Real-time acoustic emission testing based on wavelet transform for the failure process of thermal barrier coatings

AUTHOR(S)
Yang, L.; Zhou, Y. C.; Mao, W. G.; Lu, C.
PUB. DATE
December 2008
SOURCE
Applied Physics Letters;12/8/2008, Vol. 93 Issue 23, p231906
SOURCE TYPE
Academic Journal
DOC. TYPE
Article
ABSTRACT
The fracture type differentiation, quantification, and source identification are desirable and yet intractable in the acoustic emission (AE) testing of a complex coating system. In this letter, a technique combining wavelet transform and conventional AE parameter analysis was developed to study the tensile failure process of thermal barrier coatings in real time. It is demonstrated that the failure of thermal barrier coatings originates from surface vertical cracking and follows interface cracking, and that the AE count increases with tensile load following a power law. The cracking source identified from AE signals agrees well with that observed by optical microscopy. This technique provides a powerful tool for the study of failure processes of a wide range of coatings and thin films.
ACCESSION #
35886545

 

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