Analysis on thermal stress of optimized functionally graded coatings during thermal shock based on finite element simulation

Thermal barrier coatings (TBCs) are mainly coated on the high-temperature hot components for aero engines or gas turbines. TBCs can provide sufficient protection to the metal and improve the service life of the turbine blades. In this paper, three different structures of TBCs were designed, which were single ceramic layer coatings (SCLC), double ceramic layer coatings (DCLC), and optimized functionally graded coatings (OFGC). The thermal shock resistance was analyzed to investigate the effect of structure on the thermal shock failure of the coatings. The thermal stress inside the coatings during the thermal cycling of the TBCs was analyzed based on the finite element simulation. The results indicated that using a buffer layer to reduce the maximum stress value in the coating system was an effective means of increasing the coating thermal cycle service life.