6.4 Materialinformatik
Filtern
Dokumenttyp
- Zeitschriftenartikel (37)
- Vortrag (31)
- Posterpräsentation (5)
- Sonstiges (1)
- Preprint (1)
- Forschungsdatensatz (1)
Schlagworte
- Defects (12)
- Ab initio simulations (10)
- Referenzdaten (10)
- Workflows (8)
- NFDI-MatWerk (7)
- Density functional theory (6)
- Hydrogen (6)
- Thermodynamics (6)
- Ab initio thermodynamics (5)
- Multiscale simulation (5)
Organisationseinheit der BAM
- 6 Materialchemie (76)
- 6.4 Materialinformatik (76)
- 5 Werkstofftechnik (17)
- 5.2 Metallische Hochtemperaturwerkstoffe (11)
- 6.3 Strukturanalytik (5)
- 5.6 Glas (3)
- 6.0 Abteilungsleitung und andere (3)
- 3 Gefahrgutumschließungen; Energiespeicher (2)
- 3.6 Elektrochemische Energiematerialien (2)
- 5.0 Abteilungsleitung und andere (2)
Hydrogen-driven microstructural evolution in polycrystalline aluminium (Al) is strongly influenced by grain-boundary (GB) structure and hydrogen (H) segregation. We aim to develop an atomistically informed phase-field framework to describe these effects, with relevance to hydride formation. Molecular-statics simulations were performed for representative FCC Al symmetric-tilt boundaries Σ5(310), Σ5(210), and Σ3(111) to assess whether H segregation can initiate hydride formation. Instead, H induces defect-mediated structural transitions and shows distinct relaxation pathways during ingress and discharge. At high H content, the GB cleaves and free surfaces form. To generalise these insights, a library of 250 microstates was generated for each GB plane normal within the Σ5 family by sampling rigid-body translations and boundary-plane atomic fractions. This enables construction of GB energies as a function of plane normal, with temperature dependence introduced through Boltzmann weighting. H effects are included by evaluating segregation energies for the minimum-energy microstate of each plane normal, yielding H-chemical-potential-dependent GB energies. These results provide essential GB energetics for phase-field modelling of H-driven microstructural evolution in Al.
Safe, durable, and efficient storage remains a central hurdle in hydrogen economy, where metal hydrides offer a promising route, particularly for stationary applications. Among these materials, FeTi stands out as a cost-effective system capable of reversible hydrogen uptake and release under near-ambient conditions. As part of BMBF-funded collaborative project GreenH2Metals, we performed atomistic simulations aimed at elucidating experimentally observed microstructural transformations such as formation of secondary phases and hydrides. We analyzed the thermodynamic stability of competing phases using ab initio calculations and examined chemical segregation as well as heterogeneous precipitation at dislocations and planar defects. Defect phase diagrams, along with the roles of vacancies and antisite defects in bulk diffusion, are explored in detail. The impact of various tramp elements on these processes is assessed through high-throughput calculations enabled by workflow frameworks such as pyiron. Together, these computational insights support a data-driven alloy design strategy for optimizing FeTi-based materials for sustainable hydrogen storage.
A Lightweight Procedural Layer for Hybrid Experimental–Computational Workflows in Materials Science
(2026)
We present a prototype implementation of a framework for hybrid workflows that integrates automated computation and analysis with manual experimental measurements. Leveraging the pyiron workflow engine, we introduce a lightweight, parameterized procedure description layer that can adjust instrument settings and orchestrate human interventions. Rather than replacing the existing execution engine, we add a minimal abstraction layer that translates procedure descriptions into executable steps for manual operations, enabling seamless handoffs between automated tasks and manual experimental tasks. We demonstrate the approach on a use case that combines manual tensile testing with subsequent analytical evaluation and result aggregation, illustrating how parameters and metadata propagate through the workflow and how instrument state changes and measurement results are captured. We also report a usability study that quantifies the ease with which lab scientists can create and modify workflows. Finally, we summarize lessons learned from this prototype, including improved provenance capture and streamlined experimental orchestration, as well as current limitations. We conclude that the proposed lightweight hybrid workflow description offers a promising path to bridging automation, computation and manual experimentation, and we outline directions for future work.
Mechanical and thermodynamic properties, including the influence of crystal defects, are critical for evaluating materials in engineering applications. Molecular dynamics simulations provide valuable insight into these mechanisms at the atomic scale. However, current practice often relies on fragmented scripts with inconsistent metadata and limited provenance, which hinders reproducibility, interoperability, and reuse. FAIR data principles and workflow‐based approaches offer a path to address these limitations. We present reusable atomistic workflows that incorporate metadata annotation aligned with application ontologies, enabling automatic provenance capture and FAIR‐compliant data outputs. The workflows cover key mechanical and thermodynamic quantities, including equation of state, elastic tensors, mechanical loading, thermal properties, defect formation energies, and nanoindentation. We demonstrate validation of structure–property relations such as the Hall–Petch effect and show that the workflows can be reused across different interatomic potentials and materials within a coherent semantic framework. The approach provides artificial intelligence (AI)‐ready simulation data, supports emerging agentic AI workflows, and establishes a generalizable blueprint for knowledge‐based mechanical and thermodynamic simulations.
Metal-organic frameworks (MOFs), particularly the zeolitic imidazolate framework (ZIF) family, are attractive precursors for advanced energy-storage materials. Upon pyrolysis, ZIFs can be transformed into electrically conductive carbon materials while preserving their original particle morphology, which is crucial for achieving high-performance sodium-ion battery anodes. Despite these advantages, large-scale implementation remains challenging due to the need for synthesis routes that balance performance, cost, and sustainability. The present study addresses these challenges by developing environmentally benign and economically feasible strategies for the scalable production of ZIF-8-derived carbon anodes suitable for industrial applications.
The segregation of solute atoms at grain boundaries (GBs) plays a critical role in defining the mechanical properties of materials, including corrosion resistance and fracture toughness. This study investigates the structural transformations induced by minimal boron concentrations at Σ13 GBs in ferrite thin films synthesized. Two sample protocols were examined: one with carbon as the sole solute and the other with carbon and boron co-segregation. To understand the thermodynamics of such phases, we employed ab initio calculations to meticulously examine the competing Σ13 GB phases that coexist in the presence of defects and stacking faults. Building on our findings regarding these competing GB phases, we analyzed the energetic aspects of solute segregation at the GB interface. Furthermore, we constructed a defect phase diagram to gain insights into the influence of Boron concentration on the evolution of GB structure. We reveal that boron segregation transforms the GB structure from flat to zigzag trigonal prisms by forming new chemical bonds, ultimately enhancing bonding strength between boron and iron atoms by 5%. This transformation doubles steel's resistance to fracture and provides valuable insights into the thermodynamic and energetic aspects of solute-driven GB phase evolution. These findings contribute to developing innovative strategies for designing high-performance steel with enhanced mechanical integrity and durability.
Boron enhances the hardenability of low-alloyed steel and reduces embrittlement at low temperatures, at parts-per-million concentration levels. Ist effectiveness arises from segregation to grain boundaries (GBs)-planar defects- between crystals-yet atomic-scale evidence remains limited.We addressed this gap by synthesizing GBs with controllable geometry and orientation, enabling reproducible comparison with and without boron segregation. Differential phase-contrast imaging directly reveals boron at iron GBs, and in-situ TEM heating (20 °C to 800 °C) allows us to track the dynamic evolution of GB structures. We found that boron segregation induces local structural changes and triggers GB phase transformations, as corroborated by calculated GB defect phase diagrams spanning broad ranges of carbon and boron content. Our findings not only bridge a gap in understanding the interplay between GB structure and chemistry but also lay the groundwork for targeted design and passivation strategies in steel, potentially transforming its resistance to hydrogen embrittlement, corrosion, and mechanical failure.
Oxide glasses have proven to be useful across a wide range of technological applications. Nevertheless, their medium-range structure has remained elusive. Previous studies focused on ring statistics as a metric of the medium-range structure, but this metric provides an incomplete picture of the glassy structure. Here, we use atomistic simulations and state-of-the-art topological analysis tools, namely persistent homology (PH), to analyze the medium-range structure of the archetypal oxide glass (Silica) at ambient temperatures and with varying pressures. PH presents an unbiased definition of loops and voids, providing an advantage over other methods for studying the structure and topology of complex materials, such as glasses, across multiple length scales. We captured subtle topological transitions in medium-range order and cavity distributions, providing new insights into glass structure. Our work provides a robust way for extracting the void distribution of oxide glasses based on PH.
Chemically complex materials (CCMats) including high-entropy alloys, oxides, and related multi-principal element systems offer a paradigm shift in materials design by leveraging chemical diversity to simultaneously optimize functional, structural, and sustainability criteria. The vastness of the compositional and structural space in CCMats propels the field into an expanding exploratory state. To reconcile functional and structural performance across this immense parameter space remains an open challenge. This Perspective evaluates the opportunities and challenges associated with harnessing chemical complexity across a broad spectrum of applications, such as hydrogen storage, ionic conductors, catalysis, magnetics, dielectrics, semiconductors, optical materials, and multifunctional structural systems. It is delineated how three central design strategies: targeted substitution (SUB), defect engineering (DEF), and diversity management (DIV) enable the reconciliation of high functional performance with long-term structural stability and environmental responsibility.
Advances in computational thermodynamics, microstructure simulations, machine learning, and multimodal characterization are accelerating the exploration and optimization of CCMats, while robust data infrastructures and automated synthesis workflows are emerging as essential tools for navigating their complex compositional space. By fostering cross-disciplinary knowledge transfer and embracing data-driven design, CCMats are poised to deliver next-generation materials solutions that address urgent technological, energy, and
environmental demands.
Solute segregation at low-angle grain boundaries (LAGBs) critically affects the microstructure and mechanicalproperties of magnesium (Mg) alloys. In modern alloys containing multiple substitutional elements, understanding solute-solute interactions at microstructural defects becomes essential for alloy design. This study investigates the co-segregation mechanisms of calcium (Ca), zinc (Zn), and aluminum (Al) at a LAGB in a dilute Mg-0.23Al-1.00Zn-0.38Ca (AZX010) alloy by combining atomic-scale experimental and modeling techniques.Three-dimensional atom probe tomography (3D-APT) revealed significant segregation of Ca, Zn, and Al at the LAGB, with Ca forming linear segregation patterns along dislocation arrays characteristic of the LAGB. Clustering analysis showed increased Ca–Ca pairs at the boundary, indicating synergistic solute interactions.
Atomistic simulations and elastic dipole calculations demonstrated that larger Ca atoms prefer tensile regions around dislocations, while smaller Zn and Al atoms favor compressive areas. These simulations also found that Ca–Ca co-segregation near dislocation cores is energetically more favorable than other solute pairings, explaining the enhanced Ca clustering observed experimentally. Thermodynamic modeling incorporating calculated segregation energies and solute-solute interactions accurately predicted solute concentrations at the LAGB, aligning with experimental data. The findings emphasize the importance of solute interactionsat dislocation cores in Mg alloys, offering insights for improving mechanical performance through targeted alloying and grain boundary engineering.