Failure Process Analysis of Thermal Barrier Coated Cylindrical Structure under Thermal Cycling

Thermal barrier coated specimens were prepared by the plasma spraying technique.Thermal cycling experiments were carried out with infrared radiating the outer surface and forced cooling the inner surface.Finite element analysis software ABAQUS was employed to study the transient temperature and stresses in thermal barrier coatings under thermal cycling.It is showed that,the hoop tensile stress in the ceramic coat is very large when temperature reached the highest on heating up and at the beginning of cooling process,and the tensile stress exceeds the strength of ceramic coat at that time,which results in axial crack' appearance.In addition,radial stress at the ceramic coat/bond coat interface in an intact system is not able to induce interface cracks,interface cracks initiated by radial stress are affected by the presence of the axial cracks,possibly,edge effects.