Approach to determine stress strain curves by FEM supported nanoindentation

Nanoindentation is an often used method to characterize the hardness and the elastic modulus of thin coatings. Finding a method to determine the flow curve of thin coatings using analytical or numerical methods is one goal of actual nanoindenter research. In this work an approach is presented to determine the flow curve of materials using nanoindentation and finite element simulation (FEM). This method uses a FEM model of the indentation process. The determination of the flow curve is achieved by iteratively comparing experimental and simulated load-displacement curves and adapting the modelled plastic behaviour until both curves match. Analytical methods are used to determine boundary conditions for the flow curve and therefore reduce the number of possible solutions. The method is validated on material samples with known flow curves. The forecasted flow curves uniformly show good agreement with experimental measured flow curves. A critical discussion of the results and the future prospects is made.