Highlights

• Researchers successfully 3D-printed dense, crack-free Nd-Fe-B permanent magnet parts using electron-beam powder bed fusion (PBF-EB) in high vacuum, solving longstanding manufacturing challenges with this brittle, oxidation-prone material.
• Despite achieving >99.5% density and mechanical integrity, the printed magnets showed very low coercivity (~9.3 kA/m for PBF-EB), meaning they behave closer to soft magnets than high-performance permanent magnets needed for motors and robotics.
• Vacuum processing with PBF-EB minimized oxidation better than laser-based printing, but controlling solidification kinetics and grain boundary structures remains critical before 3D-printed NdFeB can replace sintered magnets in demanding applications.

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Researchers led by Markus Benjamin Wilms, University of Wuppertal (opens in a new tab), with collaborators from University of Duisburg-Essen (opens in a new tab), Natalia Shkodich, Michael Farle, Karlstad University (opens in a new tab), Pavel Krakhmalev, and others report that they can 3D-print dense, crack-free Nd-Fe-B permanent-magnet parts using electron-beam powder bed fusion (PBF-EB)—a long-standing manufacturing challenge because NdFeB is brittle and easily oxidized. The catch: while the PBF-EB parts held together mechanically and reached >99.5% density, their magnetic “hardness” (coercivity)—the property that makes a permanent magnet resist demagnetization—was very low, meaning the parts behave closer to “soft” magnets than true high-performance NdFeB. The study frames a path forward, but it also makes clear that printing a strong magnet is harder than printing a strong part.

Study Methods

The team compared two common 3D-printing routes using the same rare-earth-lean NdFeB powder (MQP-S):

• PBF-EB (electron beam) in high vacuum (~10⁻⁶ mbar) with very high build temperatures (approaching or exceeding ~1000°C in the process zone).
• PBF-LB (laser beam) in argon with limited preheating (480°C).

They then tested density, cracking, oxygen uptake, microstructure (SEM/XRD), and magnet performance (VSM/PPMS magnetization loops).

Key Findings

• PBF-EB produced crack-free, dense parts; PBF-LB parts showed major cracking and porosity despite preheating.
• Oxygen was decisive: vacuum PBF-EB minimized oxidation; PBF-LB experienced significant oxygen uptake, which harms magnet phases.
• Magnetic performance remained the bottleneck: PBF-EB coercivity reached only 9.3 kA/m (very low for NdFeB). PBF-LB coercivity was higher (127 kA/m) but still far below the starting powder and was undermined by cracking and oxidation.
• Heat treatment helped little for PBF-EB (already near equilibrium) and could worsen PBF-LB by promoting soft α-Fe formation and magnetic deterioration.

Implications for Industry and Supply Chains

This is a meaningful manufacturing signal: vacuum, high-temperature electron-beam printing can finally make intact NdFeB shapes—important for custom motors, robotics, and defense form factors.

But the “controversial” reality is that mechanical print success does not equal magnet success. Until researchers control solidification kinetics, phase balance, grain boundaries, and oxidation to raise coercivity dramatically, printed NdFeB will remain a promising prototype route—not a drop-in replacement for top-tier sintered magnets.

Limitations

The powder is rare-earth-lean, which inherently limits classic Nd-rich grain boundary structures that drive coercivity. Results also depend heavily on oxygen control, scan strategy, and thermal gradients—variables that may shift across machines and scale-up settings.

Citation: Wilms MB, Shkodich N, Shokri H, et al. High-temperature additive manufacturing of Nd-Fe-B by powder bed fusion. Progress in Additive Manufacturing (2026). https://doi.org/10.1007/s40964-026-01561-7 (opens in a new tab)