A Promising Nanostructured Lu₂Si₂O₇/Lu₂SiO₅ Environmental Barrier Coating With Exceptional Thermal Cycling Property: Design, Fabrication, and Screening

In addition to thermal barrier coatings, environmental barrier coatings have gradually become commonly used materials in high-temperature hot-section components due to their remarkable thermomechanical properties. Nevertheless, the thermal cycling durability limits the application under harsh combustion gas conditions, such as aircraft engines and gas turbines. Herein, the Lu₂Si₂O₇/Lu₂SiO₅ double-layer environmental barrier coating by introducing the concept of nanostructure was designed and fabricated, and the thermal insulation and thermal cycling properties of the coating were evaluated by using the method of integration of the finite element simulation and experimental test. These results indicate that the nanostructured Lu₂Si₂O₇/Lu₂SiO₅ environmental barrier coating with a double-layer structure of 50Lu₂SiO₅-100Lu₂Si₂O₇ exhibits the minimum thermal stress (154.23 MPa), and remains intact without peeling off after 1200 cycles at 1350°C, with excellent thermal cycling resistance. The thermally grown oxide with a thickness of 3.6 µm in the coating indicates excellent oxidation resistance. Additionally, the nanostructured Lu₂Si₂O₇/Lu₂SiO₅ coating exhibits excellent phase stability (1350°C) and thermal insulation properties. Accordingly, the nanostructured Lu₂Si₂O₇/Lu₂SiO₅ double-layer environmental barrier coating is beneficial for improving the thermal cycling durability of aircraft engines and gas turbines, addressing current limitations.