Hot corrosion behavior of BaLa2Ti3O10 exposed to calcium-magnesium-alumina-silicate at elevated temperatures

摘要

Calcium-magnesium-alumina-silicate (CMAS) attack has been regarded as one of the significant failure mechanisms for thermal barrier coatings (TBCs). In this study, CMAS corrosion behavior of BaLa2Ti3O10, a novel TBC material, is investigated at 1300 degrees C and 1350 degrees C for 0.5 h, 4 h, 12 h and 24 h. Results reveal that BaLa2Ti3O10 has high resistance to molten CMAS infiltration, attributable to the formation of a dense reaction layer. X-ray diffraction, scanning electron microscope, energy dispersive spectroscope, transmission electron microscope confirm that the layer consists of apatite, celsian and perovskite phases. With increased corrosion duration, the layer retains good phase stability and the thickness increases. The formation of corrosion products and the reaction layer are discussed according to a dissolution-reprecipitation mechanism and the optical basicity theory.