Stress Analysis of Thermal Barrier Coating's Failure under Thermal Shock

The plasma spraying technique was used to prepare a set of thermal barrier coating specimens,and water-cooling method was used in thermal shock experiments.Cracks and spallation were observed on the surface of these specimens after thermal shock.Finite element analysis software-Abaqus was employed to study the transient stresses in thermal barrier coatings under thermal shock.In this simulation,the hoop stress in top coat changed with time from tension to compression,and it exceeded the strength of top coat at the beginning of thermal shock,which induced axial cracks' appearance.In addition,interfacial radial stress and oxidation of bond coating would generate interfacial cracks.These two kinds of cracks lead to TBC's spallation together.