Effects of deposition conditions on composition and thermal cycling life of lanthanum zirconate coatings

Lanthanum zirconate (La2Zr2O7, LZ) coatings were prepared under four different deposition conditions by electron beam-physical vapor deposition (EB-PVD). The composition, crystal structure, surface and cross-sectional morphology, cyclic oxidation behavior of these coatings were studied. Elemental analysis indicates that the coating composition has partially deviated from the stoichiometry of pyrochlore, and the existence of excess La2O3 is also observed. The deviation could be reduced by properly controlling the electron beam current or by changing the ingot composition. Meanwhile, when the electron beam current was 500 – 600 mA, the thermal cycling life of the coating is superior to other coatings.