Evaluation of the elastic-plastic properties of SiCN coating system by finite element simulations

The elastic properties of SiCN coating on substrates can be evaluated by nano-indentation test, however, it is challenging for experiments to evaluate the plastic performance of SiCN coating. Finite element (FE) is a numerical method for investigating in-depth mechanical behavior of various structures. In this paper, a contact model between Berkovich indenter and SiCN/Si system is established by FE method. The stress-strain behavior of SiCN coating is obtained by comparing the calculated P-h curves with experimental results. The indentation depth dependent elastic modulus and hardness of the SiCN coating are calculated from the P-h curves and are close to the experimental data. When the indentation depth is in excess of 10% of the coating thickness, the mechanical properties of SiCN coating tend to be influenced by the Si substrate, which also consists with experiments. The proposed approach provides an efficient tool to predict the mechanical properties of SiCN coating.