Research Project Objectives / Hypothesis
The hypothesis of the proposed research project assumes that it is possible to develop an advanced numerical framework capable of reliably predicting the initiation and propagation of cracks in thin protective coatings by explicitly accounting for their complex nanostructural morphology. The proposed approach will be based on the integration of the Digital Material Representation (DMR) concept with the Finite Element Method (FEM), enabling full-field simulations that capture the influence of the real micro- and nanostructural features of coatings on their mechanical response.
Therefore, two main objectives of the research are defined:
- development of a new class of full-field numerical models for the analysis of fracture mechanisms in thin films, based on the integration of digital microstructure generators within finite element simulations,
- evaluation of the robustness and predictive capabilities of the proposed computational framework under various coating morphologies, material properties, and loading conditions.
Research Methodology
The numerical part of the project requires expertise in numerical modelling, microstructure modelling, and advanced computational mechanics. The research will rely on the development of digital microstructure generators capable of reproducing the characteristic columnar morphology of thin films obtained by deposition processes. These digital models will be integrated with finite element simulations to analyse stress distribution, crack initiation, and crack propagation in coating–substrate systems.
Finite element simulations will be performed using advanced numerical software such as Abaqus, which is available at the AGH Cyfronet computing infrastructure and can be used for large-scale simulations required in this project. Additional computational tools will be developed in-house and implemented using object-oriented programming languages such as C++, Python, and Fortran.
The experimental part of the project will focus on the characterization of thin titanium nitride (TiN) coatings deposited on various substrates including titanium, steel, aluminium, and silicon. The coatings will be produced using Physical Vapour Deposition (PVD) and Pulsed Laser Deposition (PLD) techniques. Microstructural characterization will be performed using scanning electron microscopy (SEM) and transmission electron microscopy (TEM).
Mechanical properties of the coatings and substrates will be evaluated using pico-indentation techniques supported by inverse analysis methods. In addition, focused ion beam (FIB) techniques will be used to prepare micro-samples for local mechanical testing. In-situ deformation experiments will be carried out using a picoindenter integrated with a scanning electron microscope, enabling direct observation of crack initiation and propagation mechanisms in thin films under controlled loading conditions.
Research Project Impact
Thin protective coatings are widely used in modern engineering applications, including cutting tools, aerospace components, biomedical implants, and photovoltaic systems. Their performance and reliability strongly depend on the mechanical integrity of the coating–substrate system. However, due to the complex nanostructural morphology of many deposited coatings, phenomena such as crack initiation, crack propagation, and delamination are still not fully understood.
Experimental investigations of these mechanisms are often complex, expensive, and time-consuming. Moreover, certain phenomena occurring at the micro- and nanoscales are difficult to observe directly using experimental techniques alone. Numerical simulations can therefore provide valuable complementary insight into the behaviour of such materials.
Most existing numerical approaches used to model thin coatings are based on simplified assumptions and often rely on homogenized material descriptions. These models do not explicitly account for the real morphology of coatings, such as columnar growth structures or local structural heterogeneities. As a result, their predictive capabilities in terms of crack initiation and propagation remain limited.
For this reason, the development of numerical models capable of explicitly incorporating microstructural morphology is of great importance. The proposed research aims to establish a new computational framework that combines digital material representation with finite element modelling to simulate fracture processes in thin films in a realistic manner.
The developed modelling approach will significantly improve the understanding of failure mechanisms in thin coatings and will provide new tools for the optimization of coating design and deposition technologies. Ultimately, the results of this project may contribute to the development of more durable and reliable coating systems for a wide range of industrial and biomedical applications.
