Method and apparatus for testing residual stress in coatings

摘要

Disclosed are a method and an apparatus for testing residual stress in coatings. The method includes: obtaining elastic modulus of a coating and a substrate of a target object; obtaining a temperature during the coating preparation of the target object; obtaining a cross-sectional area of the coating and a cross-sectional area of the substrate of the target object; obtaining a thermal expansion coefficient of the coating and a thermal expansion coefficient of the substrate of the target object; and calculating the coating residual stress σ_c of the target object by the following formula:; $$ {\sigma }_c=\left(\frac{S_s}{S_c}\right)·\left[1-\left(\frac{E_s{S}_s}{E_c{S}_c}+\frac{{\alpha }_c}{{\alpha }_s}\right)/\left(1+\frac{E_s{S}_s}{E_c{S}_c}\right)\right]·E_s{\alpha }_s\Delta T_c,$$wherein, S_c is the cross-section area of the coating, S_s is the cross-section area of the substrate, E_c is the elastic modulus of the coating, E_s is the elastic modulus of the substrate, α_c is the thermal expansion coefficient of the coating, α_s is the thermal expansion coefficient of the substrate, and ΔT_c is the temperature during the coating preparation.