서스펜션 플라즈마 용사법을 이용한 La₂Zr₂O 7 /YSZ 2층세라믹 열차폐코팅의 제조와 특성평가

Rare-earth zirconates, such as La₂Zr₂O 7 and Gd₂Zr₂O 7 , have been investigated as one of the candidates for replacing conventional yttria-stabilized zirconia (YSZ) for thermal barrier coating (TBC) applications at higher turbine inlet temperatures. In this study, double-ceramic-layer (DCL) TBCs of YSZ 1st layer and La₂Zr₂O 7 top coat layer are fabricated by suspension plasma spray with serial liquid feeders. Microstructures, hardness profiles, and thermal durability of DCL-TBCs are also characterized. Fabricated DCL-TBCs of YSZ/La₂Zr₂O 7 exhibit excellent properties, such as adhesion strength (>25 MPa) and electrical thermal fatigue (~1429 cycles), which are comparable with TBCs fabricated by atmospheric plasma spray.