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The pulse thermography (PT) technique was applied to the detection of the delamination of a multi-layered coating system composed of mullite/Si onto a reaction-bonded SiC substrate. The potential evaluation was carried out in order to detect internal delamination in multi-layered material system. Moreover, the observation of the cross sections and 3D views obtained by X-ray computed tomography (CT) indicated that the delamination occurred at the interface between the top coat and the bond coat layers. The changes in the temperature distribution obtained by PT indicated the existence of a delamination area in the top coat layer of the mullite. In particular, the lower temperature region corresponded to the delamination area. The experimental results confirmed that the PT technique is effective with respect to the internal delamination of multi-layered coating system.


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Detection of small delamination in mullite/Si/SiC model EBC system by pulse thermography

Show Author's information Yutaro ARAIaRyo INOUEb( )
Department of Materials Science and Technology, Tokyo University of Science, 6-3-1, Niijyuku, Katsushika-ku, Tokyo, 125-8585, Japan
Department of Mechanical Engineering, Tokyo University of Science, 6-3-1, Niijyuku, Katsushika-ku, Tokyo, 125-8585, Japan

Abstract

The pulse thermography (PT) technique was applied to the detection of the delamination of a multi-layered coating system composed of mullite/Si onto a reaction-bonded SiC substrate. The potential evaluation was carried out in order to detect internal delamination in multi-layered material system. Moreover, the observation of the cross sections and 3D views obtained by X-ray computed tomography (CT) indicated that the delamination occurred at the interface between the top coat and the bond coat layers. The changes in the temperature distribution obtained by PT indicated the existence of a delamination area in the top coat layer of the mullite. In particular, the lower temperature region corresponded to the delamination area. The experimental results confirmed that the PT technique is effective with respect to the internal delamination of multi-layered coating system.

Keywords:

environmental barrier coatings (EBCs), delamination, pulse thermography (PT), multi-layer, image processing
Received: 20 January 2019 Revised: 28 February 2019 Accepted: 22 March 2019 Published: 03 August 2019 Issue date: September 2019
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Publication history

Received: 20 January 2019
Revised: 28 February 2019
Accepted: 22 March 2019
Published: 03 August 2019
Issue date: September 2019

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© The author(s) 2019

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