In situ phase engineering during additive manufacturing enables high-performance soft-magnetic medium-entropy alloys.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 39528504.
- Also identified by DOI 10.1038/s41467-024-54133-0 and PMC identifier 11555091.
- Licence recorded as CC BY-NC-ND.
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Abstract
Additive manufacturing (AM) shows promise as a method for producing soft-magnetic multicomponent alloys for use in electric motors and sustainable electromobility applications. However, the simultaneous achievement of a high saturation magnetic flux density (B<sub>s</sub>) and a low coercivity (H<sub>c</sub>) in AM soft-magnetic materials remains challenging. Herein, we present an approach that integrates an elemental powder mixture of Fe<sub>45</sub>Co<sub>30</sub>Ni<sub>25</sub> with Fe<sub>2</sub>O<sub>3</sub> nano-oxides, which is then subjected to laser powder bed fusion (LPBF) followed by high-temperature annealing to achieve an FCC-structured Fe<sub>45</sub>Co<sub>30</sub>Ni<sub>25</sub> MEA/FeO composite. The FeO nanoparticles, a byproduct of the reaction between Fe powders and Fe<sub>2</sub>O<sub>3</sub> nano-oxides, serve as nucleation sites for the formation of a single FCC phase in the MEA matrix. The resulting LPBF MEA/FeO composite has a B<sub>s</sub> of 2.05 T and an exceedingly low H<sub>c</sub> of 115 A m<sup>-1</sup>, compared to those of the BCC/FCC dual phase MEA and other state-of-the-art additively manufactured soft-magnetic alloys. In situ Lorentz transmission electron microscope (TEM) revealed that the low H<sub>c</sub> of the FCC-structured MEA/FeO composite originates from the reduced pinning effect of grain boundaries in the FCC phase on domain wall movement compared with those in the FCC/BCC dual phase.