Elastic Analysis of a Triangular Pyramidal Indentation of a Two-Layer Thin Film

In order to evaluate the mechanical properties of a very thin film, a method combining the analysis with the experiment of triangular pyramidal indentation (the nanoindentation method) is proposed. The particular formulation of FEM of triangular pyramidal indentation is established. The indentation load-displacement relationship is obtained for a thin film sputtered or sprayed on a substrate with different mechanical properties. The effects of film thickness and mechanical properties of the film and the substrate are clarified quantitatively. Coupling the analytical results with experimental measurements enables one to determine the mechanical properties of very thin films.