Effect of Top-Coat Thickness and Interface Fluctuation on the Residual Stress in APS-TBCs

This study focused on the numerical simulation of distribution residual stress in yttria-stabilized zirconia (YSZ) coatings prepared with atmospheric plasma spraying (APS). We particularly investigated around interface between top coat and bond coat. During thermal spray deposition, droplets particles deposit substrate a complex manner, causing waviness non-uniform distribution. Therefore, is an important consideration when preparing barrier (TBCs). Residual stresses directly affect performance coats (BCs) ceramic (TCs). To accurately evaluate stress, we considered thickness conducted detailed analysis The results show that compressive exists at TC/BC interface, which may be caused by mismatch expansion coefficient YSZ substrate, potentially leading to coating delamination. Moreover, significantly increases increasing thickness. When top-coat exceeds 300 μm, concentration failure are likely occur. Meanwhile, optimized experiment confirm BC/YSZ tensile maximum value 155 MPa, consistent finite element calculation results. Furthermore, modes TBCs rough conditions discussed detail. Our research provides guidance for TBC design optimizing their performance.