New, sustainable metallic materials and their manufacturing processes are the focus of the DaMic research project. Its sub-projects, eleven in total, aim to help set up a new field of research at the interface of digitalisation and sustainability.
Metallic materials like steel are produced by melting and alloying and are moulded by means of processes such as casting, forging or welding. Their production is currently at the source of 40 per cent of all industrial greenhouse gas emissions. In addition, large quantities of harmful by-products arise when they break down. It is therefore imperative that the metallic materials of the future become more sustainable. The DaMic priority programme funded by the German Research Foundation (DFG) is intended to lay the scientific foundations for this.
The programme’s focus is on digital and data-driven methods for material design, which are to be used to develop materials that are more environmentally friendly, easier to recycle and still able to perform well. Two basic approaches are being pursued: materials that manage with fewer chemical additives (alloying elements) and alloys that are particularly tolerant of impurities from secondary raw materials such as steel and scrap iron.
Recyclability and sustainability of high-speed steels
The sub-project, in which Prof. Dr Arne Röttger from the University of Wuppertal is participating, focuses on new forms of so-called lean high-speed steel (HSS for short). These new forms are primarily used for metal-cutting tools such as drills, milling cutters and circular saw blades. Specifically, the project is concerned with developing design methods based on computer simulations and machine learning in order to automatically optimise the complex relationship between the chemical composition, microstructure and properties of the steels and map them in a digital material model.
“Higher wear resistance or improved properties, such as strength, often extend service life, and a lean alloy design makes it easier to recycle these steels. HSS has a short service life under operation; the result of that is many cycles of recycling and large quantities of material recycled each year. So, the potential benefits of new high-speed steels are considerable,” emphasises Arne Röttger.
The tool steel identified during the research process is manufactured and tested to assess its actual performance and potential limitations. Further optimisations are then carried out until the new alloy concept is conclusive.
Sustainable copper materials for 3D printing
The next generation of lightweight, environmentally friendly aluminium alloys for 3D printing is being developed by the sub-project in which Dr Silja Rittinghaus is conducting research at the University of Wuppertal. Conventional high-performance alloys often use rare and expensive alloying elements, such as scandium and lithium. This makes them costly to produce and difficult to recycle. The project approaches them in a different way. Says Rittinghaus: “We focus on aluminium alloys with readily available, non-critical alloying elements that can be easier to recycle, more sustainable and yet strong enough for mechanically demanding applications.”
By combining modern 3D printing technologies with powerful computer models and artificial intelligence, the project is investigating how alloy recipes and microstructures can be optimised quickly and efficiently. The team’s long-term goal is not only to provide more environmentally friendly metals, but also to create a roadmap for accelerated alloy development, paving the way to a circular, resource-efficient economy.
Crossover steels based on scrap recycling
Crossover steels are mixtures of different types of stainless steel, which thanks to their high scrap content can be produced from one hundred per cent recycled material. However, these steels still need to be thoroughly analysed. Their chemical composition will differ greatly from the conventional, standardised grades and the proportion of accompanying elements such as phosphorus, sulphur and copper will inevitably be increased by the scrap content. These elements can result in problematic contamination and hence damage to the material.
Therefore, the project in which Prof Dr Jaan-Willem Simon from Wuppertal is involved is investigating how steel can be made stronger and more durable along with the role that is played by the slightest damage inside the material. “With the aid of high-throughput experiments, during which a high number of variants are tested simultaneously instead of successively, and of artificial intelligence we analyse many different mixtures of scrap in order to understand how impurities influence the properties of steel and how recycled steel can nevertheless be used specifically for high-performance applications,” Simon explains.
Source: idw
