Evaluation of the thermal insulation performance and stress distribution of SiC/YSZ thermal barrier coatings via finite element simulation

• Higher SiC nw content boosts crack resistance but reduces thermal insulation. • Thicker YSZ, thinner TC1, and low SiC nw content ensure higher thermal insulation. • Regulating SiC nw content helps to control interfacial stress. • The 2S n 2S p Y and 3S n 1S p Y show 31 % and 45 % longer thermal shock lifetime than YSZ. Crack initiation and propagation are key factors limiting the lifetime of yttria-stabilized zirconia (YSZ) thermal barrier coatings (TBCs). The incorporation of silicon carbide nanowires (SiC nw ) and particles (SiC p ) can significantly improve their lifetime, but it may potentially affect thermal insulation and the distribution of thermal stresses. This study used finite element simulation to analyze the effects of varying SiC nw and SiC p contents on the thermomechanical behavior of YSZ composites, to assess their thermal insulation and stress distribution as an interlayer, and to verify thermal shock performance through coating preparation. Results indicated that increasing SiC nw content increased the thermal conductivity, elastic modulus, and critical J-integral of the composites, while decreasing the coefficient of thermal expansion. A high SiC nw content effectively alleviates interfacial stress concentration during the cooling stage, but may impair thermal insulation performance. A balanced approach to these two issues can be achieved through rational structural design. Thermal shock performance demonstrates that adjusting the SiC nw to SiC p ratio significantly extends coating life, particularly at higher nanowire content. This study provides a theoretical basis for optimizing the design and development of YSZ TBCs materials and coatings.