Speaker
Description
Additive manufacturing of Nd-Fe-B permanent magnets through laser powder bed fusion of metals (PBF-LB/M) provides opportunities for microstructural manipulation leading to novel combination of properties. Additivation of the feedstock powder with Ag nanoparticles (NPs) improves the coercivity of PBF-LB/M-produced Nd-Fe-B magnets by 17 ± 6% in as-built conditions (935 kA/m) compared to the unadditivated counterpart. To advance the understanding of the associated mechanisms, we use atom probe tomography (APT) and show that Ag-nanoadditivation leads to a fine dispersion of Ag-rich nanophase regions, on which the main 2:14:1 magnetic phase nucleates heterogeneously. This refines the magnetic particle size distribution, which, along with a change in phase composition in comparison to the unmodified feedstock, explains the improved properties.
