Large deformation simulations of cyclic displacement instabilities in thermal barrier systems
نویسندگان
چکیده
The cyclic displacement instability exhibited by a thermally grown oxide (TGO) in a thermal barrier system has been simulated using a scheme that embodies large-scale thickening. The investigation has three main objectives. (i) A sensitivity study that probes the influence of the thermo-mechanical properties of the bond coat. It uses properties that closely resemble those relevant to actual bond coat materials. (ii) Explore the influence of the size of the imperfections present on the bond coat surface and address the critical size below which the instability is suppressed. (iii) A determination of the influence of TGO growth kinetics ranging between linear and parabolic. 2002 Acta Materialia Inc. Published by Elsevier Science Ltd. All rights reserved.
منابع مشابه
The displacement of the thermally grown oxide in thermal barrier systems upon temperature cycling
Models that characterize the displacement instability of the thermally grown oxide (TGO) found in some thermal barrier systems are reviewed, consolidated and extended. It is demonstrated that the simulations are only consistent with the observations whenever the bond coat and TGO both undergo plastic deformation. The TGO yields at the peak temperature, during growth, while the bond coat yields ...
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