Progress on high-entropy and nanostructured thermal protective coatings for aero-engines

Because of excellent corrosion resistance, high temperature resistance, and low thermal conductivity, ceramic coating can play a protective role on the surface of hot end parts of aero-engines. The most representative ones are thermal barrier coatings (TBCs) and environmental barrier coatings (EBCs). The TBCs are used for thermal insulation protection of high-temperature alloy hot-end components (mainly turbine blades), while EBCs are used for protection against ceramic matrix composites. The differences between traditional thermal barrier ceramic coatings and high entropy and nano-sized thermal barrier ceramic coatings were compared in the aspects of the mechanical, thermophysical, and corrosion resistance properties, and two rare earth silicates in EBC and their common failure modes were reviewed; the future development direction of high entropy and nano-ceramic coatings in aero-engines was prospected.