This project is a joint project of the De Magnete group and the Atom Probe Tomography group, and was initiated by MPIE’s participation in the CRC TR 270 HOMMAGE. We also benefit from additional collaborations with the “Machine-learning based data extraction from APT” project and the Defect Chemistry and Spectroscopy group.
Magnetic materials are key components of energy conversion devices and thus improving the material’s magnetic properties is critical to enhance the sustainability of power generation and conversion. We use atom probe tomography (APT) to study the relationship between the microstructure on the nanoscale and the properties of various soft and hard magnetic materials. As demonstrated by experiments and machine-learning aided analysis, the changes in magnetic properties, e.g., magnetization, coercivity, Curie temperature and domain structure, are closely related to the variation of magnets’ microstructure. Our results help guide the design of magnetic materials.
Several magnetic systems are currently under active investigation: NdFeB, Sm(Co,Fe), CeCoCu magnets as hard magnetic alloys and CoFeNiTaAl high-entropy alloys as soft magnets.
Fig: APT 3D map of the Sm2(Co,Fe,Cu,Zr)17 show different spatial arrangement of the three phases depending on the region: magnetic Cu-rich (blue) and Zr-rich (green) cell boundary phases inside Fe-rich matrix cell phase (grey).
Fig: APT 3D map of the Sm2(Co,Fe,Cu,Zr)17 show different spatial arrangement of the three phases depending on the region: magnetic Cu-rich (blue) and Zr-rich (green) cell boundary phases inside Fe-rich matrix cell phase (grey).
International researcher team presents a novel microstructure design strategy for lean medium-manganese steels with optimized properties in the journal Science
The objective of the project is to investigate grain boundary precipitation in comparison to bulk precipitation in a model Al-Zn-Mg-Cu alloy during aging.
Understanding hydrogen-microstructure interactions in metallic alloys and composites is a key issue in the development of low-carbon-emission energy by e.g. fuel cells, or the prevention of detrimental phenomena such as hydrogen embrittlement. We develop and test infrastructure, through in-situ nanoindentation and related techniques, to study…
The goal of this project is the investigation of interplay between the atomic-scale chemistry and the strain rate in affecting the deformation response of Zr-based BMGs. Of special interest are the shear transformation zone nucleation in the elastic regime and the shear band propagation in the plastic regime of BMGs.
About 90% of all mechanical service failures are caused by fatigue. Avoiding fatigue failure requires addressing the wide knowledge gap regarding the micromechanical processes governing damage under cyclic loading, which may be fundamentally different from that under static loading. This is particularly true for deformation-induced martensitic…
Hydrogen embrittlement (HE) of steel is a great challenge in engineering applications. However, the HE mechanisms are not fully understood. Conventional studies of HE are mostly based on post mortem observations of the microstructure evolution and those results can be misleading due to intermediate H diffusion. Therefore, experiments with a…
Understanding the deformation mechanisms observed in high performance materials, such as superalloys, allows us to design strategies for the development of materials exhibiting enhanced performance. In this project, we focus on the combination of structural information gained from electron microscopy and compositional measurements from atom probe…
Deviations from the ideal, stoichiometric composition of tcp (tetrahedrally close-packed) intermetallic phases as, e.g., Laves phases can be partially compensated by point defects like antisite atoms or vacancies, but also planar defects may offer an opportunity to accommodate excess atoms.
Smaller is stronger” is well known in micromechanics, but the properties far from the quasi-static regime and the nominal temperatures remain unexplored. This research will bridge this gap on how materials behave under the extreme conditions of strain rate and temperature, to enhance fundamental understanding of their deformation mechanisms. The…
