LZC/YSZ DCL TBCs by EB-PVD: Microstructure,low thermal conductivity and high thermal cycling life

Thermal barrier coatings (TBCs) with low thermal conductivity have triggered tremendous attention due to their promising application in the gas turbine engines. Albeit recent studies have investigated double ceramic layers (DCL) with pyrochlore (A₂B₂O₇) phase, it still remains a big challenge for controlling element content and investigating the relationship between the complex hierarchical architectures and their thermal performances. Here we describe a series of DCL La₂O₃-ZrO₂-CeO₂ (LZC)/Y₂O₃-stabilized ZrO₂ (YSZ) coating under different current of electron beam by electron beam-physical vapor deposition (EB-PVD). The formation of hierarchical architecture with feathery microstructure and intra-columnar have been investigated in detail. The DCL coatings achieve a high thermal cycling life and relatively low thermal conductivity at controlling current of electron beam from 1.0 A to 1.3 A. This work may open new opportunities to rationally design other promising TBCs.