LPBF-processed high-density Nd-Fe-B Magnets: From gas atomized powders

Nd-Fe-B permanent magnets are crucial for high-performance applications, yet their fabrication by laser powder bed fusion (LPBF) is limited by defects, microstructural instability, and degradation of magnetic properties. This work examines printability, microstructure evolution, and defect formation in two Nd-rich gas-atomized Nd–Fe–B powders (Alloy A and Alloy B) as a function of laser power, scan speed, and hatch spacing. X-ray computed tomography (XCT) reveals that Alloy A consistently achieves > 99% relative density but attains a maximum coercivity of 0.58 kOe, whereas a specific processing condition for Alloy B reaches ∼99.99% density with a coercivity of 0.49 kOe at higher energy input. These results demonstrate that the optimal LPBF processing window is strongly composition dependent, and the resulting insights provide practical guidelines for tailoring process parameters to improve the performance and reliability of Nd-Fe-B permanent magnets.