Research progress in fabrication technologies and failure mechanisms of environmental barrier coatings

With the development of aero-engine technology， the rising operating temperature makes the service environment of environmental barrier coatings （EBCs） increasingly severe， imposing higher demands on their comprehensive performance. EBCs have evolved from the first-generation mullite/YSZ system to the fourth-generation thermal/environmental barrier coatings （T/EBCs）， among which rare-earth silicates have become a research hotspot owing to their excellent high-temperature stability and matched thermal expansion coefficient. This paper reviews typical EBCs preparation processes including APS， EB-PVD and PS-PVD， analyses the influence of process parameters on coating quality， and elaborates the typical failure mechanisms under water-vapor corrosion， CMAS attack and thermal cycling stress. Future development of EBCs will focus on high-entropy materials， multi-scale structural design and intelligent process optimization to further improve their service performance and lifetime.