Micro-Damage Analysis of Interface in Thermal Barrier Coating System by Particle Binding Layer Model

Abstract

In this paper, finite element analysis for wrinkled interface in thermal barrier coating was performed. Particle binding layer model for an imperfect cohesion between ceramic thermal spray particles was developed here. Microstructure model consisted of ceramic coating, which is including a particle binding layer, and metallic bond coating layers with the wrinkled interface was used for examining the wrinkled interface stress filed in thermal barrier coating system. The analytical results showed that stress increases between peaks of the wrinkled interface in the side of ceramic coating layer when the microstructure model is subjected to transverse loading. The site of maximum stress was almost coincided with the micro crack initiation site observed in a cross section of the specimen. Energy release rates and stress intensity factors for isolated and periodic aligned small cracks in microstructure model with the wrinkled interface were shown with the term of the closed form.