Key Words: EHLA, Simulation, Coatings, Multiscale

Multiscale Modelling of Additively Manufactured Layered Materials: The Key to More Durable Coatings?

Severe surface wear is a challenge wherever high mechanical loads occur – be it in aerospace, the automotive industry or high-performance machinery. To improve surface durability, specialised coatings are applied. These coatings must be able to withstand extreme pressures, high temperatures and high frictional forces while maintaining their functionality.

The robustness of these coatings is not only determined by their chemical composition. Their microstructure and the residual stresses created during manufacturing also play a critical role. Modern simulation methods allow for the analysis of coating behaviour under various load conditions, providing valuable insights for targeted optimization.

The Limitations of Conventional Simulation Methods

Traditional simulation approaches either focus on the macroscopic properties of an entire component or examine microscopic mechanisms at the particle level. However, it is at the intersection of these scales that the most important processes occur: microcracks, dislocations and phase transitions that significantly affect the wear and life of the coating.

This is where multiscale modelling comes into play—a method that integrates different scales to provide a more precise overall picture.

Our New Research Project: Multiscale Modelling of the Mechanical Behaviour of Additively Manufactured Coatings

In our upcoming interdisciplinary research project, conducted within the Research Area Digital Material in collaboration with the Institute for Applied Materials – Reliability and Microstructure at Karlsruhe Institute of Technology (KIT), we will investigate these complex interrelations. Our goal is to gain a deeper understanding of how coatings behave under mechanical stress in high-performance applications and how we can systematically improve their durability.

What Is Multiscale Modelling and How Does It Work?

The mechanical properties of a material result from interactions at multiple levels. Multiscale modelling allows this behaviour to be analysed at different scales:

Atomic scale: Chemical bonds, diffusion processes, and lattice structures define the material’s fundamental behavior.
Microscale: Grain structure, particle distribution, and microstresses determine how the material deforms under load and whether cracks or plastic deformation occur.
Mesoscale: The interaction of microscopic defects influences macroscopic behavior—this is where material fatigue and failure originate.
Macroscale: The overall behavior of the component, which ultimately determines its suitability for real-world applications.

Multiscale modeling combines different simulation approaches to link these levels, including:

Finite Element Methods (FEM) for analyzing stresses and deformations at the macro level.
Discrete Dislocation Dynamics to understand how defects grow and propagate within the material.

Our Research Focus

Our project investigates how additively manufactured metal matrix composite (MMC) coatings can be optimized. We use three-phase research approach:

Process Simulation and Microstructure Analysis
Using models of laser metal deposition (e.g., HS-DED) and microstructural analysis of real samples, we investigate how temperature gradients, particle distribution, and residual stresses influence the microstructure.
Micro- and Mesoscale Modeling
We analyze how particles and the matrix material deform under load, where weak spots develop, and how cracks initiate and propagate.
Optimization of Material Parameters
The knowledge gained from the first two steps help us define improved material parameters to develop more durable and resistant coatings.

By linking micro- and macroscales through scaling techniques, we can make more accurate predictions about how coatings will perform in real-world conditions and what microstructural adjustments will improve their performance.

Our Key Research Objectives

We aim to develop a comprehensive physical understanding of how the structure and properties of additively manufactured MMC coatings behave under mechanical loading. This knowledge will be used to systematically optimize material properties. A key focus will be on the interaction between the coatings’ microstructure and their mechanical performance in real-world applications.

A key aspect of our research is identifying the crucial factors influencing the lifespan and resilience of these coatings. To achieve this, we combine experimental investigations with advanced simulations, creating a data-driven modelling approach. These insights allow us to refine process parameters and material compositions to significantly improve coating performance.

Furthermore, we are investigating the transferability of our findings to other material systems. Our goal is to develop scalable models and methodologies that can be applied across multiple industries, extending the impact of our research and driving innovation in high-performance coatings.

Where Our Research Makes a Difference

Our findings will be valuable for both scientific research and industrial applications. By improving coatings, we can extend component lifetimes, reduce maintenance costs, and promote more sustainable production processes.

Who Benefits?

Industry (Automotive & Aerospace): Higher-quality coatings lead to longer service life and lower maintenance effort.
Materials Scientists & Engineers: New insights enable the further development of existing models and innovative simulation approaches.
Additive Manufacturing Manufacturers: Precise process control results in higher-quality, longer-lasting coatings.
Sustainability & Environment: More durable materials reduce resource consumption and waste generation.

Our research project has the potential to provide valuable contributions toward the development of high-performance and sustainable material solutions.

This project is funded by the German Research Foundation (DFG).