Residual Stress Characteristics of Ceramics Coating

Abstract

The residual stress of metal to ceramic laminates (Al₂O₃/Nb, Y₂O₃/Nb, stabilized ZrO₂/Nb) produced by solid state bonding was studied. Two typical models, disk coated on one side with different materials and disk coated on both sides were chosen for finite element method (FEM) analysis. The results indicated that the dimensionless residual stress at the ceramic coating decreases with increasing the coating thickness ratio, h_c/h_s, and the elastic modulus ratio, (1-μ_s)E_c/((1-μ_c)E_s). The four point bending strength at room temperature for sintered ceramics (Al₂O₃, Y₂O₃, stabilized ZrO₂) enabled us to estimate critical heating temperature for ceramics coating from the analysis of residual stress described above.