Determination of the elastic modulus of a nanocoating using a three-point bending test

Abstract

Technologies for creating nanocoatings with unique properties on polymeric materials are being actively developed and used in human activities. The possibilities of using such composite materials will depend on the physical and mechanical properties of the coatings. To determine the mechanical characteristics of nanocoatings on polymeric materials, there are used nanoindentation methods. The results of nanoindentation of a hard coating are significantly affected by a soft polymer substrate. On the other hand, there are various experimental methods and analytical models for determining the mechanical properties of materials at the macroscopic level. The use of these approaches would make it possible to obtain the values of the mechanical properties of nanocoatings, which could be used to calculate and analyze the stress-strain state of products with nanocoatings. In this study, we demonstrate the application of a three-point bending test to determine the elastic modulus of a carbonized nanolayer formed by high-energy nitrogen ion treatment of a polyurethane surface. By selecting the optimal thickness of the test samples, it is possible to create conditions for determining the modulus of elasticity of a nanolayer on a polymer substrate using a three-point bending test. We have obtained statistically significant differences between the values of the elastic modulus of untreated and plasma-treated samples. Using a composite beam model, the modulus of elasticity of the carbonized nanolayer was determined.