Materials Science and Engineering A
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 on thermal cycling. The trends oppose. Namely, the TGO displacement is diminished by increasing the high temperature strength of the bond coat, but is increased upon increasing the TGO strength. The model rationalizes certain experimental trends, particularly the decrease in durability as the hot time per cycle decreases. Interactions between the instability and cracks in the thermal barrier layer are discussed.
Karlsson, A. M., Hutchinson, J. W., and Evans, A. G., 2003, "The Displacement of the Thermally Grown Oxide in Thermal Barrier Systems upon Temperature Cycling," Materials Science and Engineering: A, 351(1-2) pp. 244-257.
NOTICE: this is the author’s version of a work that was accepted for publication in Materials Science and Engineering A. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Materials Science and Engineering A, 351, 1-2, June 24, 2003, DOI:10.1016/S0921-5093(02)00843-2