New Sustainable Fe-rich Magnet using a predictive Alloy and Microstructure Design Toolbox

Nd-Fe-B magnets are central to both green mobility and the generation of electricity from renewable resources. But the need to incorporate heavy rare earths like Tb and Dy –highly critical raw materials– to operate these magnets above 100 °C (required for electric vehicles and wind turbines) makes them very costly, environmentally damaging, and with a very fragile value chain. And despite four decades of effort, no practical alternative to Nd-Fe-B has been found. SmFe12-based compounds have superior intrinsic magnetic properties, actually surpassing those of benchmark Nd-Fe-B and, without the need for additional heavy rare earths. The challenge with SmFe12 is phase instability in the bulk form and creating a microstructure that will convert the large intrinsic anisotropy field into a usable coercivity. What we know so far is that the solution lies in combining multiple alloying elements, each one impacting differently. In Sm(Fe,M,X,Z)12, for example, 20 alloying elements results in around ≈10^8 combinations (“experiments”), if each element varies from 1 to 15 at.% in quinary compositions. MAG-TOOL will create a cutting-edge toolbox that combines experimental techniques with state-of-the-art machine-learning algorithms, eliminating the need for trial-and-error. This breakthrough approach drastically reduces the number of experiments from a daunting ≈10^8 down to a manageable ≈10^2. MAG-TOOL will achieve that by breaking the multi-element complexity, starting to predict the compounds with useful phases using only three elements. This knowledge will be transferred to multi-element situations and combined with robust experiments to deliver superior magnetic properties in powders and melt-spun ribbons. MAG-TOOL will also include a laser-deposition, additive-manufacturing system for rapidly creating many compositions within the same bulk samples through compositional gradients. The outcome of the project will be the new medium- and high-performance sustainable magnet.