Incorporation of local TiN thin films heterogeneities into the full-field hybrid fracture model based on the digital material representation (DMR) concept - research data

<p>Manufacturing and processing new materials with enhanced performance often require specific treatments involving different process temperatures, complex plastic deformation paths, or varying pressures. While these improvements offer benefits, they typically come at the cost of increased energy consumption, which is neither economically nor environmentally favourable. However, there are new processes available that can produce modern composite structures with enhanced properties by combining different conventional materials. One such process is the deposition of thin films, which allows for the combination of two materials with distinct properties.
Thin films are well-known for their ability to improve mechanical, thermal, strength, biocompatibility, and visual parameters. They find applications in various fields, such as protecting the surfaces of drills, jet engine components, artificial heart valves, or photovoltaic coatings. Understanding the behaviour of thin films under loading conditions is crucial, particularly in evaluating their strength. The complex columnar structure of thin films, resulting from the deposition process, often leads to uncontrolled delamination and cracking during operation, posing a significant challenge in providing reliable protection.<br />
<p>Analyzing the fracture mechanisms of thin films using experimental methods is complicated and time-consuming. Therefore, the project proposes the development of advanced numerical models based on the concept of digital material representation. These models will accurately capture the complex morphology of thin films and enable a detailed analysis of the local fracture. The project is divided into two parts, with the first part focusing on experimental studies to analyze the morphology of titanium nitride (TiN) thin films deposited using pulsed laser deposition (PLD) and physical vapour deposition (PVD) methods on different substrates such as titanium, steel, aluminium, and silicon. Scanning and transmission electron microscopes will be used for characterization purposes. The mechanical properties of the thin films and substrates will be tested using a picoindentation. Subsequently, the thin films will be cut and deformed under in-situ test conditions using a picoindenter integrated with a scanning electron microscope (SEM) to investigate the influence of film morphology on fracture initiation and propagation.<br />
<p>In the second part of the project, digital representations of thin films in 2D and 3D space will be created using image analysis algorithms, synthetic reconstruction models, and physics-based models of the deposition process. The experimental data and developed models will be used to identify critical parameters for crack initiation and propagation, which will then be verified through complex numerical simulations based on the finite element method. The proposed approach aims to bridge the gap between laboratory tests and simulations by developing accurate and representative numerical models to study the mechanisms of crack formation in thin films. This method has the potential to significantly reduce the time and cost associated with analyzing the strength of thin films, thereby opening up new possibilities for designing structures with desired properties. Integrated computational materials engineering will provide valuable insights for optimizing thin film design and improving their performance in various applications.<br />

<p>The presented solution is just a proof-of-concept, and there are numerous challenges to be addressed and further research to be conducted to make it robust for the scientific community. <br />

<p>The innovative nature of the project and its progress beyond the current state-of-the-art can be summarised as follows:<br />

<b><h4>1. Development of a new hybrid full-field numerical model based on fracture mechanics algorithms. The project includes the development of an advanced numerical model based on fracture mechanics algorithms to accurately simulate and predict the behaviour of thin films under various loading conditions.</h4><br />
<h4>2. Development of numerical solutions for the digitalisation of morphology of thin films. The project focuses on developing techniques and algorithms to accurately recreate the morphology and microstructure of thin films in statistically similar digital material representation models.</h4><br />
<h4>3. Development of discrete methods (MD, kMC) for designing deposition processes. In the project, the molecular dynamics (MD) and kinetic Monte Carlo (kMC) methods will be used to simulate and design the deposition processes of physical vapour deposition (PVD) and pulsed laser deposition (PLD) to provide physics-based digital material representation models.</h4><br />
<h4>4. The use of state-of-the-art laboratory capabilities for evaluation of fracture initiation and propagation. The project includes the development of experimental methodologies to investigate the mechanisms of fracture initiation and propagation in thin films under loading. These laboratory tests provide also valuable data for validating the numerical models and understanding the fracture behaviour of thin films.</h4><br />
<h4>5. Mapping MD, MC, and CA simulation results to FEA meshes. The project focuses on developing methodologies to transfer the results obtained from MD, MC, and CA simulations to finite element analysis (FEA) meshes. This allows the integration of atomistic and mesoscale simulation results with numerical models created in commercial FEA software.</h4><br />
<h4>6. Complex strength analysis of thin films considering morphological characteristics. The research aims to develop advanced numerical tools and models for analysing the mechanical properties and strength of thin films, taking into account the influence of their morphological characteristics. This allows for more accurate predictions and design optimisation of thin films.</h4><br />
<h4>7. Automation of complex numerical model creation for fracture simulation. The project aims to develop automated procedures and tools for creating complex numerical models specifically tailored for fracture simulation using commercial FEA software. This streamlines the modelling process and reduces the time and effort required for designing and analysing thin films.</h4></b><br />