Finite element simulations of thermal stress distribution in thermal barrier coatings with different mullite whisker arrangements

In recent years, thermal barrier coatings (TBCs) have been extensively employed to safeguard turbine engine blades against high temperatures and harsh operating conditions. Mullite whiskers are frequently utilized to improve the mechanical properties of ceramic matrix composites because of their exceptional characteristics. This study investigates thermal stress in coating systems by analyzing the impact of varying content, aspect ratio, and deflection angle of mullite whiskers using finite element simulations under static conditions. Results demonstrated that incorporating mullite whiskers can mitigate the sudden stress variation between the ceramic coating and the substrate. The addition of mullite whiskers reduced the maximum stress value in the coating system, thereby enhancing its thermal stability and service life. The arrangement of mullite whiskers was controlled during the preparation procedure to ensure their proper orientation. The coating system exhibited higher mechanical properties at a certain position. This study provided a theoretical basis for the design of mullite whisker-reinforced TBCs.