Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1506721 | Solid State Sciences | 2008 | 11 Pages |
The interface cohesion greatly affects the longevity of thermal barrier coatings (TBCs). The adherence and stress of the interface between the bond-coat and the thermally grown oxide (TGO) are considered as crucial properties governing the life times of TBCs. In this paper, the electron density of the bond-coat/TGO interface of TBCs was calculated with the empirical electron theory in solid and molecules. The calculation results of the electron density of the bond-coat/TGO interface with various bond-coat aluminium contents were analyzed in the views of interface bonding force, interface stress and interface stability. It is shown that the suitable aluminium content of the bond-coat should be in the ranges of 8–10 wt% and about 2 wt% considering the bond-coat/TGO interface only. Taking the bond-coat/top-coat interface of TBCs into account, combining the consideration of the TGO forming ability, the suitable aluminium content becomes about 8 wt% and a little less than 8 wt%, which accords better with actual TBC applications. The deduction not only can be a useful reference to the composition design of the bond-coat of TBCs, but also shows the necessity of considering the electron density parameters of the interfaces of bond-coat/top-coat and bond-coat/TGO simultaneously in the composition design of the bond-coat of TBCs.
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