Title

Fabrication of highly dense isotropic Nd-Fe-B nylon bonded magnets via extrusion-based additive manufacturing

Publication Date

4-3-2018

Department

Ames Laboratory; Materials Science and Engineering

Campus Units

Ames Laboratory, Materials Science and Engineering

OSTI ID+

1436033

Report Number

IS-J 9704

DOI

10.1016/j.addma.2018.04.001

Journal Title

Additive Manufacturing

Volume Number

21

First Page

495

Last Page

500

Abstract

Magnetically isotropic bonded magnets with a high loading fraction of 70 vol.% Nd-Fe-B are fabricated via an extrusion-based additive manufacturing, or 3D printing system that enables rapid production of large parts. The density of the printed magnet is ∼ 5.2 g/cm3. The room temperature magnetic properties are: intrinsic coercivity Hci  = 8.9 kOe (708.2 kA/m), remanence Br  = 5.8 kG (0.58 T), and energy product (BH)max = 7.3 MGOe (58.1 kJ/m3). The as-printed magnets are then coated with two types of polymers, both of which improve the thermal stability as revealed by flux aging loss measurements. Tensile tests performed at 25 °C and 100 °C show that the ultimate tensile stress (UTS) increases with increasing loading fraction of the magnet powder, and decreases with increasing temperature. AC magnetic susceptibility and resistivity measurements show that the 3D printed Nd-Fe-B bonded magnets exhibit extremely low eddy current loss and high resistivity. Finally, we demonstrate the performance of the 3D printed magnets in a DC motor configuration via back electromotive force measurements.

DOE Contract Number(s)

AC05-00OR22725; AC02-07CH11358

Language

en

Department of Energy Subject Categories

36 MATERIALS SCIENCE

Publisher

Iowa State University Digital Repository, Ames IA (United States)

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