Analysis for Residual Stress and Deformation of Coated Member Using Inherent Strain Method

Abstract

The characteristics of residual stress and deformation of thermal sprayed plates, that are the most important property from the view point of production technique for preventing the cracking and delaminating of coatings, have not always been made clear. In this paper, the residual stress and deformation behaviors of rectangular plate, induced by the inherent strain of coating layer due to thermal spraying, was analyzed using the finite element method. It was confirmed that the dimensionless parameters of σ·(1-v_c)/(E_c·ε₁) and u·T/(L²·ε₁) was useful for presenting the residual stress and deformati, on characteristics of thermal sprayed plates. (σ: residual stress, v_c: Poisson's ratio of coating, E_c: Young's modulus of coating, ε₁: inherent strain of coating layer, u: displacement. T: thickness of substrate and L: length of substrate) It was found that the inherent strain of coating layer, that was calculated by the deformation of thermal sprayed plates, was almost constant in case of the atmospheric plasma sprayed CoNiCrAlY over IN 738 LS substrate.