Modeling of micro-crack growth during thermal shock based on microstructural images of thermal barrier coatings

Based on digital image processing theory and finite element mesh generation principle, a methodology is proposed to model the micro-crack growth of thermal barrier coatings (TBCs) during thermal shock with the aid of finite element program. Firstly, a microstructural image of plasma sprayed TBCs is transferred to digital image; secondly, a finite element grid model is generated by thresholding segmentation according to the actual microstructure; finally, based on the finite element grid model. the Tuler-Butcher failure criterion is employed to model the micro-crack growth of TBCs during thermal shock. The numerical simulation result agrees well with the experimental result, and the methodology presented in this paper is found to be effective to model the micro-crack growth. (C) 2009 Elsevier B.V. All rights reserved.