Oxidation Resistance of Plasma-Sprayed Double-Layered LC/YSZ Coatings with Different Thickness Ratios at High Temperatures

This study aims to enhance the oxidation resistance of ceramic coatings through designing and optimizing microstructure. A series of double-layered lanthanum–cerium oxide (LC) and 8 wt% yttria-partially-stabilized zirconia (YSZ) coatings with different thickness ratios were tailored. The isothermal oxidation experiment and molecular dynamics simulation results suggested that due to the lower oxygen ionic diffusion coefficient, double-layered LC/YSZ coatings exhibited an excellent antioxidation property compared to the single-layer YSZ coating. However, with the increase of LC layer thickness in LC/YSZ coatings, sintering-induced vertical cracks were easily formed within LC layer, which significantly shortened the oxidation resistance of LC/YSZ coatings by a burner rig test at 1225 °C. The equivalent thermal growth oxide thickness manifested that the optimum thickness ratio between LC and YSZ layers was 1:2.