Numerical analysis of crack evolution in PVD-deposited TiN-coated steel sheets under loading conditions

Titanium nitride (TiN) coated steel sheets are widely utilized across various industries, offering tailored solutions for diverse applications. Manufacturers appreciate its adaptability and precision, utilizing it to create intricate components for electronics, packaging, and specialized industrial equipment. In construction and design, TiN coated sheet enables crafting detailed architectural elements and custom fixtures, providing strength and corrosion resistance. One of the methods used for the production of such coated films is the PVD (Physical Vapour Deposition) process. However, electron and scanning electron microscopy analysis reveals the frequent occurrence of a complex columnar nanostructure of the deposited TiN film resulting from the specific nature of the PVD process. The morphology of such nanostructure is one of the main reasons for uncontrolled delamination and fracture observed in films during, e.g., stamping processes. Accurate investigation of film behavior during forming and exploitation conditions requires a series of very sophisticated laboratory experiments, which are time-consuming and expensive. Therefore, in this work, a new approach to the numerical analysis of the crack evolution of deposited films based on the digital material representation concept is proposed. A series of microstamping simulations were carried out as a case study to evaluate the model capabilities. The study proved that the model based on digital material representation can be used for reliable predictions of the local material behaviour of sheets with deposited complex films.