Host: The Japan Society of Mechanical Engineers
Name : [in Japanese]
Date : November 02, 2019 - November 04, 2019
Thermal barrier coating (TBC) exhibits elastic anisotropy between parallel and perpendicular directions to the spraying direction due to the laminated structure. An understanding of the anisotropic elastic property allows us to improve the durability and reliability of the coating, where the component layers are subjected to mechanical load such as thermal stress and centrifugal force. However, there are few reports on the elastic anisotropy of such coatings because conventional methods fail to measure all the elastic constants. In this study, we evaluated the anisotropic elasticity of TBC by the mode-identified resonant ultrasound spectroscopy, that is, the combination of resonant ultrasound spectroscopy and vibrational-mode identification by laser Doppler interferometry. We also studied the influence of thermal treatment on the elastic property. Our measurements revealed that the thermal barrier coating showed strong anisotropy in Young’s modulus: the value in the spray direction is much lower than inplane value. Moreover, thermal treatment enhanced Young’s modulus in both directions and weakened its anisotropy. These phenomena are consistently explained by the sintering of TBC.
