Abstract
This paper highlights our recent discoveries associated with improving the reliability and life of next-generation metallic and ceramic turbine components via re-thinking and re-designing the multifunctionality of a few coating systems. For SiC/SiC ceramic matrix composites, we found that a pre-delaminated ZrO2 coating, prepared by chemical vapor deposition (CVD), could serve as an intrinsically oxidation resistant interphase while providing the weak interface behavior desired for the composites. Stress-rupture results show that the ZrO2 coating, when its nucleation behavior is properly controlled, can provide outstanding composite performance at 950 and 1200°C. Our approach appears to provide a unique solution to the posting problem associated with state-of-the-art SiC/SiC composites containing a BN fiber coating. For Ni-based superalloys, we developed a novel procedure to prepare a ∼150 nm thick α-A12O3 layer directly on the superalloy surface. Oxidation results show that such a layer has profound effects on the phase contents and morphological evolutions of thermally grown oxide (TOO) and significantly reduces the TOO growth rate. Implications of the oxidation results are discussed in the context of optimizing the multifunctionality (i.e., thermal insulation and oxidation resistance) of next-generation thermal barrier coatings.
Original language | English |
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Pages (from-to) | 137-144 |
Number of pages | 8 |
Journal | Materials Science Forum |
Volume | 426-432 |
Issue number | 1 |
DOIs | |
State | Published - 2003 |
Event | Thermec 2003 Processing and Manufacturing of Advanced Materials - Madrid, Spain Duration: 7 Jul 2003 → 11 Jul 2003 |
Keywords
- Chemical vapor deposition
- Fiber coating
- Oxidation
- Thermal barrier coatings