Rare earth oxides stabilized La2Zr2O7 TBCs: EB-PVD, thermal conductivity and thermal cycling life

Abstract

A series of rare earth oxides stabilized La2Zr2O7 coatings by electron beam-physical vapor deposition (EB-PVD). The complex hierarchical architectures are composited of feathery nanostructure and intra-columnar pores. The obtained coating shows relativity high thermal cycling lifetime (395 cycles) and thermal shock lifetime (2201 cycles). The coatings show an especially low thermal conductivity and low thermally grown oxide growth rate. The growth behavior of thermally grown oxide (TGO) layer can be fitted in a parabolic TGO growth law (0.1651 μm2/h). The selection and optimization of rare earth oxides can be extended to design other new ceramic materials.