Evaluation of the elastic-plastic properties of TiN coating by nanoindentation technologies using FEM-reverse algorithm

Various methods have been employed to extract the elastoplastic properties of coating materials. In this work, the Levenberg-Marquardt optimization algorithm is integrated with the finite element (FE) analysis, and different hardening models are utilized to characterize the elastic plastic mechanical properties of the coating materials. Based on load-displacement curves obtained from different models such as the Swift unsaturated model and the Voce saturation model, it can be optimized to obtain a set of material properties. The sensitivity of the model parameters of the load-displacement curve is analyzed. The elastoplastic properties of the nanoindentation curve of TiN coating are extracted. The results show that yield stress, elastic modulus and the initial stage of the stress-strain curve can be impressively consistent, but are less accurate when it comes to large strain ranges.