Abstract
Lab scale additive manufacturing of Fe-Nd-B based powders was performed to realize bulk nanocrystalline Fe-Nd-B based permanent magnets. For fabrication a special inert gas process chamber for laser powder bed fusion was used. Inspired by the nanocrystalline ribbon structures, well-known from melt-spinning, the concept was successfully transferred to the additive manufactured parts. For example, for Nd16.5-Pr1.5-Zr2.6-Ti2.5-Co2.2-Fe65.9-B8.8 (excess rare earth (RE) = Nd, Pr; the amount of additives was chosen following Magnequench (MQ) powder composition) a maximum coercivity of µ0Hc = 1.16 T, remanence Jr = 0.58 T and maximum energy density of (BH)max = 62.3 kJ/m3 have been achieved. The most important prerequisite to develop nanocrystalline printed parts with good magnetic properties is to enable rapid solidification during selective laser melting. This is made possible by a shallow melt pool during laser melting. Melt pool depths as low as 20 to 40 µm have been achieved. The printed bulk nanocrystalline Fe-Nd-B based permanent magnets have the potential to realize magnets known so far as polymer bonded magnets without polymer.
Highlights
For melt-spun material it is well-known [8,11]: In decoupled magnets (high coercivFor melt-spun material it is well-known [8,11]: In decoupled magnets the hard magnetic Fe14Nd2B grains are separated by a paramagnetic Nd-rich magnets) the hard magnetic Fe14 Nd2 B grains are separated by a paramagnetic Nd-rich intergranular film
A feasibility study was successfully performed to demonstrate that the concept of nanocrystalline Fe-Nd-B magnets can be transferred from melt-spinning to additive manufacturing technology to realize bulk nanocrystalline Fe-Nd-B based permanent magnets
For additive manufacturing a special inert gas process chamber was necessary to safely handle the Fe-Nd-B based powders which are extremely sensitive to oxidation
Summary
Academic Editors: Chang-Hwan Choi and Chunlei Qiu. Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations. Additive manufacturing of functional materials offers interesting opportunities: components of complex geometry, efficient use of material and tailored properties. Functional Fe-Nd-B permanent magnet material is important for high-power motor applications. Additive manufacturing of Fe-Nd-B so far mainly focused on processing
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
