Abstract
The residual stress of metal-ceramic laminates prepared by solid state bonding was studied for coating with a linear expan-sion coefficient larger than that of a cylindrical substrate. Two typical models, inner and outer coated cylinders, were chosen for finite element method (FEM) analysis to investigate the effect of axial length of the cylinder on the residual stresses at the coating layer. The results indicated that the dimensionless residual stress at the coating layer decreased with increasing coating thickness ratio and Young's modulus ratio for inner and outer coated cylinders. The residual stress at the coating layer increased with increasing axial length of cylinder, and the tangential stress at inner coating layer increased with in-creasing axial length of cylinder. The tangential stress at the outer coating layer was always larger than the axial stress, which means that the longitudinal cracking can easily occur in comparison with the circumferential cracking. However, for Ec/Es>1, the tangential stress at the inner coating layer smaller than the axial stress, which means that the cracking behavior depends upon Young's modulus ratio.
