Evaluation of Mechanical Properties of Ductile Films on Brittle Substrates Based on the Representative Strain

Abstract

A new approach to extract the mechanical properties of ductile thin films on brittle substrates based on the representative strain (corresponding to the representative stress) has been presented in depth-sensing indentation with finite element method (FEM). Forward and reverse analyses of high deformation symmetry numerical simulation of Berkovich indentation tests are used to determine mechanical properties of ductile films. The proposed reverse analysis provides a new solution for the initial yield stress (or the representative stress) and the strain-hardening exponent, given that the Young’s modulus is predetermined from the Sakai method, e.g., as [1]. The validity of the reverse analysis method is checked using the numerical nano-indentation test.