ISSN:
1573-4803
Source:
Springer Online Journal Archives 1860-2000
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Abstract An investigation was carried out to determine the comparative performance of selected bond coats representing the diffusion aluminides and overlays in thermal barrier coating systems. Emphasis was placed upon oxidation behavior, thermal stability, and failure mechanism. Isothermal oxidation tests were carried out attemperatures in the range of 1000 °C to 1150 °C. Scanning electron microscopy combined with energy dispersive x-ray spectroscopy, x-ray diffraction, and transmission electron microscopy were used to characterize the coating microstructure. Among the bond coats examined, overlays exhibited the best performance followed by Pt-aluminides and simple alunimides for a given alloy substrate. However, for all types of bond coats, failure of the coating system occurred by decohesion of the oxide scale at the oxide-bond coat interface. All bond coats examined were found to be degraded by oxidation and interdiffusion with the alloy substrate permitting the formation of non-protective oxide scale near the bond coat surface. Platinum as well as active elements such as Hf and Y were identified as key elements in improving the performance of thermal barrier coating systems.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1004825932601
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