Circular Materials

Circularity isn't just a buzzword; it's an imperative for our future. This symposium will take a magnified look at circular material strategies, bridging the gaps between today's challenges and tomorrow's solutions. As we sift through case studies, from the efficient production of products that are designed for circularity to innovative r-strategies like re-cycling or re-manufacturing, attendees will gain important insights into sustainable material utilization. Together, we will pave the way for a world where materials, be it metals, polymers, ceramics, or composites, contribute to sustainable development. Also, sustainability assessment in a holistic way of the circular technologies and concepts will be a part of this symposium.

Achieving high-value circularity in aluminium demands the integration of advanced digital methodologies across both the first and second life of components. This symposium, jointly organized by the Horizon Europe projects Digi4Circular and RecAL, convenes over 25 industrial and academic partners to present and discuss technical advances enabling circularity at material, component, and system levels.

First, focus is on circularity-by-design for aluminium components, leveraging computational materials engineering to optimize alloy composition and microstructure for both primary and recycled feedstocks. Speakers will detail the interplay between alloying strategies, casting process parameters, and the resulting mechanical properties—demonstrating how digital twins and integrated simulation workflows can predict and validate component performance using high-recycled-content alloys. The Digi4Circular methodology, combining digital product passports (DPP), rapid life cycle assessment (LCA), and component design, will be showcased as a blueprint for embedding traceability and sustainability from the outset.

For second-life processes, RecAL will introduce a digitally connected Circularity Hub, enabling real-time data exchange between dismantling, sorting, and remelting operations. Technical sessions will address sensor-driven sorting, AI-assisted alloy classification, and the paradigm shift towards dynamic inventory data—allowing upcycling of post-consumer scrap into high-specification alloys. The role of digital marketplaces and interoperable data spaces in closing the loop will be critically examined.

The symposium will address both wrought and cast alloys, highlighting process-structure-property relationships and the digitalization of every step in the aluminium value chain. By uniting design, validation, and process innovation, we aim to bridge the gap between linear and circular economies, identify current industrial bottlenecks, and propose actionable solutions for data-driven circularity.

We invite researchers, industry stakeholders, and policymakers to join this technically focused discussion, advancing the accuracy, efficiency, and practical implementation of circular economy principles for aluminium.

Materials at the end of their lifetime represent large masses that burden local economies, societies and environment due to their limited direct recyclability and reusability. On the other hand, such materials represent a large untapped source of elements, compounds and critical raw materials (CRMs) that can be with proper processing extracted and reused. The recycling and reuse of end-of-life materials is crucial to environmental sustainability that can be also economically valuable, particularly when rare, critical and hard-to-produce materials are in view.

Another hurdle is the large amount of industrially produced side streams, i.e. unwanted byproducts and wastes, that plague and burden a substantial amount of the globe with the necessity to reprocess them or dispose of them properly with minimal environmental impact. However, with further technological development and the reducing quality of available ores and sources, the side streams are viewed increasingly as alternative unconventional sources for technologically relevant elements and compounds.

The symposium will act as a forum for exchange of ideas and highlighting current challenges of sustainable reprocessing and sourcing valuable materials from end-of-life materials and waste streams. The symposium intends to host experts from engineering and science fields, industry and policymakers to discuss new avenues of exploration, innovation and research. We invite contributions related (but not limited) to the following selected topics:

• Sustainable recycling of end-of-life materials (inorganic materials i.e.: oxides, alloys, composites, functional materials, etc.)
• Innovative sustainable reprocessing of industrial waste materials
• Alternative use of end-of-life and waste materials
• Disruptive technologies for extraction of high-value and CRMs
• Full circular recycling and reuse process chains and technologies
• Novel processing procedures for beneficiation of industrial wastes and side streams

Metals play salient roles in our society and civilization, while their production still contributes significantly to the industrial CO2-emissions. Increasing the recycling can drastically reduce the emissions as well as the environmental impact, but metal recycling alone cannot fulfill the future market demands, as they are forecast to further increase at least until the end of the century. Besides, an increase in recycling fraction leads to accumulation of impurity elements in metals deteriorating product quality and possibly leading to downcycling. Therefore, advances in both carbon-lean primary and secondary metallurgical approaches are urgently needed to mitigate the negative environmental impact and enable circular metals, as well as the introduction of new methods to metal design like recycling friendly alloy designs, lifecycle assessment or material flow analyses.

This symposium focuses on fundamental and applied research in the field of sustainable metallurgy to support the disruptive technology shifts in the metal industry (incl. steel, aluminum, nickel, manganese, titanium, etc.). Topics of particular interest include, but are not limited to:

• Sustainable metallurgy approaches of ferrous and nonferrous metals using renewable energy resources, e.g., renewable hydrogen and electricity, biomass, etc.
• Sustainable alloy designs which enable the usage of increased scrap fractions as well as low-quality raw materials
• Metallurgical approaches addressing the issue of accumulating impurities in recycled metals
• Strategies for efficient utilization of low-grade input materials and industrial wastes in metallurgical sectors
• Fundamental understanding of physical, chemical, and mechanical phenomena in sustainable metallurgical processes
• Re-use and re-manufacturing approaches for construction metals
• Lifecycle assessment as a tool for sustainable material development

Additionally, this symposium will contain a special session entitled “Circular E-Car”, which will discuss material concepts for increasing the circularity of electric vehicles.

The urgent demand for high-performance, resource-efficient structural materials necessitates a paradigm shift in how alloys are discovered, designed, and optimized. This symposium will spotlight recent advances in accelerated materials development and sustainable alloy design, with a particular focus on how these have been enabled by high-throughput processing and experimentation, automated testing and characterization, machine learning methods, integrated computational materials engineering, and combined experimental and data-driven approaches.

The symposium focuses on accelerating materials development through high-throughput processing, autonomous experimentation, AI-integrated simulations, and closed-loop design. At the same time, it emphasizes sustainable alloy design via recyclable, lean, and impurity-tolerant alloys, alternative processing, and microstructure engineering—guided by predictive and data-driven tools. Key topics include linking composition, process, and structure to performance, hybrid design strategies, and fostering interdisciplinary exchange to enable faster, more sustainable materials innovation. The symposium fosters exchange across materials science and data science to advance sustainable structural materials.Topics to be covered in the symposium include, but are not limited to, the following:

• Machine learning and AI for alloy design, process optimization, and data analysis
• Accelerated alloy discovery via automated processing, high-throughput characterization, and rapid testing
• Sustainable alloy design using secondary raw materials, lean/impurity-tolerant alloys, and low-energy processing
• Microstructure engineering for performance and resource efficiency
• Simulation-based and hybrid (data + experimental) approaches for alloy and process optimization
• Composition–process–microstructure–property–performance linkages and design strategies
• Innovative manufacturing technologies including additive manufacturing and advanced processes for tailored properties
• Case studies and interdisciplinary approaches integrating materials science, data science, and sustainability

Driven by the high potential of hydrogen technologies to support the transition to sustainable green energy industries, material development across the hydrogen supply chain, e.g. hydrogen generation infrastructure, hydrogen storage, hydrogen transportation, has gained great attention in the last decade. One hot topic has been the use of hydrogen as an energy vector i.e., for powering fuel cells in cars or trains, or piped into home appliances as a substitute for natural gas. Another important use for hydrogen is in heavy industry e.g., in green steel production, where H2 is being examined as a lasting alternative to extract iron from its ore. Regardless of the final application, hydrogen needs to be stored and transported to the point of use. For efficient H2 storage and transportation, innovative metallic materials are required. These materials must achieve specific properties e.g., resistance to hydrogen embrittlement, tolerance to very low temperatures (for liquid H2), higher strength (often required for lightweighting), and good storage density or reversibility (for solid state H2 storage).

This symposium addresses the recent progress of fundamental research of future materials and the current-in-use materials, e.g. material redesign by defect engineering, dopants, etc, for hydrogen applications. Topics on hydrogen uptake, diffusion, and trapping, hydrogen effect on material integrity, i.e. hydrogen embrittlement, surface reactions, as well as the development of novel advanced hydrogen-tolerant metallic materials using multi-scale and multi-spatial experimental and simulation approaches are very much welcome. This symposium aims to bring together interdisciplinary engineers and researchers who are dedicated to advancing the fundamental and applied research on hydrogen effects in metallic materials, and serve them a platform for sharing knowledge, discussing cutting-edge methodology and exchanging research experience.

• Exemplary topics and contributions are sought at the symposium include but are not limited to:
• Novel materials design and processes for H2 energy, e.g., H2 production, metal hydride systems for solid state H2 storage, liquid hydrogen transportation, combustion, etc.
• Impact of environmental conditions (e.g., in the presence of gaseous H2 or H2 generated from electrochemical reactions, low temperature, high pressure) on the hydrogen embrittlement sensitivity and on mechanical properties degradation of metallic materials.
• Characterization of hydrogen - metal interaction, hydrogen diffusion and trapping, as well as evaluating compatibility or performance of metallic materials in H2, using both experiments and simulations, including simulations from atomic up to the structural scale, e.g., density functional theory (DFT), molecular dynamics (MD) and kinetic Monte Carlo (KMC) simulations, finite element modeling (FEM), etc. and advanced characterization technology/testing methods, e.g., using sub-size specimens, thermal desorption spectroscopy (TDA), high-resolution transmission electron microscopy (HRTEM), atom probe tomography (APT) and slow strain rate tensile (SSRT) test.
• Weldability and joint performance of metallic materials for H2 pressure vessels and pipes.
• Fundamental research by numerical modelling of hydrogen diffusion in metallic materials and fracture to predict hydrogen induced failures and analyze the influence of process parameters on hydrogen embrittlement.
• Development of next generation hydrogen-mobility and hydrogen-safety metallic materials for lightweight hydrogen storage and transport.
• Design of hydrogen-tolerant metallic materials by artificial intelligence-aided approaches.