"Soft" magnetic materials are standard components in electromagnetic generators (such as wind turbines) and electric motors (such as those in electric cars) as well as intelligent systems consisting of sensors and actuators. These are of great importance for the digitalisation of our society and industry as well as the development of smart cities. They are expected to be transformation drivers towards a more sustainable circular economy and a globally renewable energy system that supports economic and social development. However, their functional and mechanical properties can be significantly improved. Non-ideal magnetic properties can lead to loss of efficiency or material failure. It is thus desirable to develop materials with improved properties.
In "Magnificent" we aim to produce a new class of soft magnetic materials, based on high entropy alloys (HEAs), with superior magnetic properties. HEAs consisting of at least 5 different elements coexisting in atomically disordered structures are little explored. Variable elemental compositions can lead to unexpected and promising properties and functionalities as compared to existing soft magnets. We use digitized approaches in material selection and synthesis based on machine learning and Additive Manufacturing.
Samples with various compositions based on the FeCoNiMnAl, FeCoNiMnGe and FeCrNiMnGe systems have been produced with Laser Metal Deposition (LMD). Critical for the material development are characterization methods at the micro and nano level. These methods have provided a quick assessment for the selection of the most suitable materials with respect to their magnetic and structural performance. We started with the FeCoNiMnAl material system and used magneto-optical imaging as well as scanning electron microscopy with X-ray analysis for a quick assessment of the magnetic behaviour and microstructure. More detailed analysis has been performed using high-resolution electron microscopy, electron and X-ray diffraction methods and magnetic force microscopy (MFM).
We have focus on correlated methods where local structure and chemistry are linked to the magnetic properties. In parallel with the experimental activities, we have performed theoretical modelling to connect the measured magnetic properties with the composition and microstructure of the samples. 3 representative compositions of the FeCoNiMnAl system in the as-printed and heat-treated state have been extensively studied. During 2022, we focused on the FeCoNiMnAl system produced with both LMD and a Melt Spinning process performed by our international partners in Slovak Academy of Sciences. In addition, Kerr Microscopy was conducted by our international partners at the Manchester University in order to measure the magnetic hysteresis loops in selected areas of the LMD samples, allowing estimates of the local coercivity to be made. Lorentz Microscopy is used to investigate the magnetic performance in selected samples and establish a correlation between magnetic domain walls movements and defects in the alloys.
Our results from 2021, indicating that we achieved our goal to produce HEAs with soft magnetic properties have been tested further to confirm reliability during 2022. The material structure is very complex and further basic research is needed for a deeper insight and understanding. This will delay the project going into a higher TRL (5-6), but the recent outstanding results make it worth it.
The project aims to promote theoretical and methodological renewal and national competence in relevant materials research. In line with responsible research and innovation principles (RRI), we establish health and safety protocols for raw materials and products in accordance with life cycle considerations in existing national and European directives. In an RRI context, "Magnificent" will hold an open dialogue with various stakeholders through seminars and workshops. During 2022, four oral presentations were given at conferences (two digital and two physical) and two peer reviewed article were published while additional manuscripts are at the preparation stage.
Conversion between movement and electricity has become a critical part of the global renewable energy system, with wind mills and electric vehicles as prominent examples. Soft magnetic materials are in the heart of electromagnetic generators and electric motors, but there is still much to desire from their functional and mechanical properties. Non-ideal magnetic properties may lead to fatigue and loss of generation efficiency or even mechanical failure. The present project aims to introduce a new generation of materials for soft magnets: high entropy alloys (HEA) generated with additive manufacturing (AM). HEA have demonstrated surprising combinations of properties in various fields, and a few recent works have indicated that this may also be the case for soft magnetic materials. Furthermore, the rich compositional freedom in these materials implies huge possibilities of tailoring functional and mechanical properties to specific applications. The goal of Magnificent is to identify novel HEA-based soft magnets with superior magnetic properties that exhibit significantly reduced losses and fatigue compared to the current state-of-the-art. At the same time, processing by AM facilitates net shape construction of complex geometries and potentially low-emission, distributed production. The project constitutes a complete suite of synthesis and characterization tools, facilitating screening of a large number of potential candidate materials in the search of optimal compositions. In addition, modelling efforts will contribute to the screening by suggesting new materials as well as rationalizing experimental results. But first and foremost, the project partners have endorsed the principles of responsible research and innovation, with specific actions on health, environment, and safety, proactive ethical principles, and a comprehensive risk assessment.