Interaction effects of anisotropic roughness interface and component shape characteristics on fatigue life of thermal barrier coatings

The objective of this study is to investigate the interaction effects of anisotropic roughness interface (ARI) and component shape characteristics on the thermal fatigue life of thermal barrier coatings (TBCs). In this study, an ARI characterization method for 3D TBCs interfaces of circular tubes is established. Then, TBCs finite element model and TBCs thermal fatigue life prediction model based on particle swarm optimization are conducted. Finally, the effect of ARI on the interface stress state and thermal fatigue life of the TBCs is discussed. The results show that the maximum error in the fatigue life prediction model of TBCs is only 45.3%, and the fatigue life prediction error for TBCs under similar operating conditions is only 30.8%. When the axial interface wavelength is 0.060 mm and the circumferential wavelength interface is 0.057 mm, the maximum equivalent stress at the interface is the smallest, with a value of 241.4 MPa. The thermal fatigue life is maximum when the axial wavelength interface is 0.060 mm and the circumferential wavelength interface is 0.049 mm, with the value of 639 cycles, which is the 47.6% increase in fatigue life compared with the initial roughness TBCs model (The interface wavelengths are all 0.040 mm). The above findings demonstrate the effectiveness of ARI in enhancing the fatigue life of TBCs, which provides a new idea for the preparation of high fatigue life TBCs.