Thermal stresses of ceramic coatings on Zr-2.5%Nb alloy

Based on the principle of complementary energy, an analytical method is developed and verified, which focuses on the end effects for determining the thermal stress distributions in a coated beam. This method gives stress distributions that satisfy the stress-free boundary conditions at the edges. A numerical example is presented to verify the approach. The results show that the shear and peeling stress distributions along the interface between the substrate and the coating are significant near the edges, and become negligible in the interior region. The developed method is applied to compare the thermal stress distributions along the interface between two different ceramic coatings (i.e., ZrO2-8%Y₂O₃ and ZrO₂-SiO₃) on the same alloy (Zr-2.5%Nb), which is the material used for making the pressure tubes of a pressurized heavy water reactor (PHWR).