Refining the Microstructure of Fe‐Nd‐B by Selective Laser Melting

Abstract

Lab scale additive manufacturing of Fe‐Nd‐B based permanent magnet material (Fe75‐Nd18‐B7) has been performed. For fabrication a special inert gas process chamber for laser powder bed fusion has been used. This is required because Fe‐Nd‐B powders are extremely sensitive to oxidation. Selective laser melting (SLM) of the powders allows to realize very fine microstructures with a directed crystal growth and finely dispersed Nd‐rich phase. It is shown, that this fine and textured microstructure leads to large coercivity in sintered Fe‐Nd‐B magnets. A prototype has been realized by milling the SLM alloy and sintering.