Numerical modeling of fracture during nanoindentation of the TiN coatings obtained with the PLD process

Abstract. In order to improve mechanical, frictional or biocompatibility behavior of well know materials like titanium (Ti) or titanium nitride (TiN) scientists are trying to develop new manufacturing and processing operations. One of those methods, that provide interesting results, is called deposition process. During deposition a material is upgraded with new surface layers that are characterized by specific required properties. These layers have usually different mechanical properties in comparison with a substrate material. A combination of different properties of the deposited layers can significantly change behavior of the structure under an exploitation condition. However, layers have usually nanometer scale, which causes problems with performing standard plastometric tests. One of the possibilities to solve this issue is an application of specially designed tests like nanoindentation. Nanoindentation can provide valuable information regarding mechanical and strength behavior of nanostructure components. These investigations are of importance to properly identify and design properties of the mentioned deposited materials. Unfortunately, experimental analyses at these scales are usually very expensive. That is why Authors decided to develop a numerical model of the nanoindentation test to investigate material behavior under loading conditions that can support experimental research. The overall aim of this research is development of a failure model, which can take into account morphology of microstructure of ceramic TiN layer deposited on the silicon substrate. Modeling of crack behavior was realized on the basis of the extended finite element method (XFEM)