Application of the spherical indenter for determination of the elastic modulus of coatings

Abstract

In this work a study of nanoindentation of the surface of epoxypolyester-based powder coatings deposited on steel substrates was carried out. The effect of the test method on the identifiable mechanical properties is investigated. The measurement results obtained by using a spherical indenter and a Berkovich indenter are compared. Estimates of reduced modulus of elasticity, Young's modulus and rigidity of coatings are obtained. The experimental data obtained indicate a significant dependence of the determined mechanical properties of the paint and varnish coatings depending on the type of indenter used. In the case of Berkovich indenter, the Young's modulus of coatings (0.6 GPa) is understated in relation to coating properties known from macro experiments (3 GPa). Using a spherical indenter, Young's modulus is overestimated (6.3 GPa).