Abstract
Magnetoplumbite-type LaMgAl11O19 with high thermal stability and excellent sintering resistance has been proposed as a promising thermal barrier coating (TBC) material for next generation gas turbines. However, LaMgAl11O19 shows poor stability at 1500 degrees C in humid environments caused by H+/Mg2+ ionic exchange. In this work, a LaZnAl11O19 coating which is supposed to possess enhanced anti-deliquescent property was produced by plasma spraying and its properties as a potential TBC were comprehensively investigated. The results show that the thermal conductivity of the as-sprayed LaZnAl11O19 coating ranges from 1.24 W m(-1) K-1 to 1.46 W m(-1) K-1 and the average thermal expansion coefficient is less than 6.0 x 10(-6) K-1 due to the presence of an amorphous phase in the as-sprayed coating. During exposure to 1300 degrees C, a total porosity of similar to 10.5% can be maintained even after 1000 h aging, indicating a high sintering resistance. Besides, nano-sized grains recrystallized from the molten lamellae give the LaZnAl11O19 coating enhanced mechanical properties. In 1100 degrees C furnace cyclic testing, the LaZnAl11O19/YSZ double-ceramic-layer TBC exhibits a thermal cycling lifetime of similar to 669 cycles, which is about 1.7 and 1.16 times as long as the conventional YSZ coating and the LaMgAl11O19/YSZ TBC, respectively. The results indicate that LaZnAl11O19 might be a promising candidate for advanced TBC applications.
| Dokumententyp: | Zeitschriftenartikel |
|---|---|
| Fakultät: | Geowissenschaften > Department für Geo- und Umweltwissenschaften |
| Themengebiete: | 500 Naturwissenschaften und Mathematik > 550 Geowissenschaften, Geologie |
| ISSN: | 2052-1553 |
| Sprache: | Englisch |
| Dokumenten ID: | 83983 |
| Datum der Veröffentlichung auf Open Access LMU: | 15. Dez. 2021, 15:10 |
| Letzte Änderungen: | 15. Dez. 2021, 15:10 |
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