Influence of Cyclic Thermal Loading on Fatigue Behavior of Thermal Barrier Coatings.pdf

PROCEEDINGS OF WORLD ACADEMY OF SCIENCE, ENGINEERING AND TECHNOLOGY VOLUME 26 DECEMBER 2007 ISSN 1307-6884 Influence of Cyclic Thermal Loading on Fatigue Behavior of Thermal Barrier Coatings Vidyasagar H. N., S. Gopal Prakash, Shivrudraiah, and K. V. Sharma guarantee the coupling between the ceramic and the airfoil Abstract—Thermally insulating ceramic coatings also known as material; during service operations, the oxidation of BC at thermal barrier coatings (TBCs) have been essential technologies to high temperatures produces a thermally grown oxide (TGO) improve the performance and efficiency of advanced gas turbines in scale located between BC and TC. The thickness of this layer service at extremely high temperatures. The damage mechanisms of increases with increasing operation time and this element air-plasma sprayed YSZ thermal barrier coatings (TBC) with various microstructures were studied by microscopic techniques after thermal seems to be almost the most important factor in determining cycling. The typical degradation of plasma TBCs that occurs during lifetime of a coated component [6-7]. cyclic furnace testing of an YSZ and alumina coating on a Titanium alloy are analyzed. During the present investigation the effects of topcoat thickness, bond coat oxidation, thermal cycle lengths and test temperature are investigated using thermal cycling. These results were correlated with stresses measured by a spectroscopic technique in order to understand specific damage mechanism. The failure mechanism of former bond coats was found to invol