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Title: Direct-write 3D printing of NdFeB bonded magnets

Abstract

We report a method to fabricate Nd-Fe-B bonded magnets of complex shape via extrusion-based additive manufacturing (AM), also known as 3D-printing. We have successfully formulated a 3D-printable epoxy-based ink for direct-write AM with anisotropic MQA NdFeB magnet particles that can be deposited at room temperature. The new feedstocks contain up to 40 vol.% MQA anisotropic Nd-Fe-B magnet particles, and they are shown to remain uniformly dispersed in the thermoset matrix throughout the deposition process. Ring, bar, and horseshoe-type 3D magnet structures were printed and cured in air at 100°C without degrading the magnetic properties. Lastly, this study provides a new pathway for fabricating Nd-Fe-B bonded magnets with complex geometry at low temperature, and presents new opportunities for fabricating multifunctional hybrid structures and devices.

Authors:
 [1];  [2];  [1];  [3];  [4];  [1];  [5];  [2]
  1. Univ. of Tennessee, Knoxville, TN (United States). Dept. of Mechanical, Aerospace, and Biomedical Engineering
  2. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Chemical Sciences Division
  3. Univ. of Tennessee, Knoxville, TN (United States). Dept. of Materials Science and Engineering
  4. Ames Lab., Ames, IA (United States). Critical Materials Inst.
  5. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Materials Science & Technology Division
Publication Date:
Research Org.:
Ames Laboratory (AMES), Ames, IA (United States); Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Org.:
USDOE Office of Energy Efficiency and Renewable Energy (EERE), Advanced Manufacturing Office (EE-5A)
OSTI Identifier:
1342934
Report Number(s):
IS-J-9070
Journal ID: ISSN 1042-6914
Grant/Contract Number:
AC05-00OR22725
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
Materials and Manufacturing Processes
Additional Journal Information:
Journal Name: Materials and Manufacturing Processes; Journal ID: ISSN 1042-6914
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; 3D printing; bonded magnets; direct-write; magnetic properties; NdFeB

Citation Formats

Compton, Brett Gibson, Kemp, James William, Novikov, Timofei V., Pack, Robert Cody, Nlebedim, Cajetan I., Duty, Chad Edward, Rios, Orlando, and Paranthaman, M. Parans. Direct-write 3D printing of NdFeB bonded magnets. United States: N. p., 2016. Web. doi:10.1080/10426914.2016.1221097.
Compton, Brett Gibson, Kemp, James William, Novikov, Timofei V., Pack, Robert Cody, Nlebedim, Cajetan I., Duty, Chad Edward, Rios, Orlando, & Paranthaman, M. Parans. Direct-write 3D printing of NdFeB bonded magnets. United States. doi:10.1080/10426914.2016.1221097.
Compton, Brett Gibson, Kemp, James William, Novikov, Timofei V., Pack, Robert Cody, Nlebedim, Cajetan I., Duty, Chad Edward, Rios, Orlando, and Paranthaman, M. Parans. 2016. "Direct-write 3D printing of NdFeB bonded magnets". United States. doi:10.1080/10426914.2016.1221097. https://www.osti.gov/servlets/purl/1342934.
@article{osti_1342934,
title = {Direct-write 3D printing of NdFeB bonded magnets},
author = {Compton, Brett Gibson and Kemp, James William and Novikov, Timofei V. and Pack, Robert Cody and Nlebedim, Cajetan I. and Duty, Chad Edward and Rios, Orlando and Paranthaman, M. Parans},
abstractNote = {We report a method to fabricate Nd-Fe-B bonded magnets of complex shape via extrusion-based additive manufacturing (AM), also known as 3D-printing. We have successfully formulated a 3D-printable epoxy-based ink for direct-write AM with anisotropic MQA NdFeB magnet particles that can be deposited at room temperature. The new feedstocks contain up to 40 vol.% MQA anisotropic Nd-Fe-B magnet particles, and they are shown to remain uniformly dispersed in the thermoset matrix throughout the deposition process. Ring, bar, and horseshoe-type 3D magnet structures were printed and cured in air at 100°C without degrading the magnetic properties. Lastly, this study provides a new pathway for fabricating Nd-Fe-B bonded magnets with complex geometry at low temperature, and presents new opportunities for fabricating multifunctional hybrid structures and devices.},
doi = {10.1080/10426914.2016.1221097},
journal = {Materials and Manufacturing Processes},
number = ,
volume = ,
place = {United States},
year = 2016,
month = 8
}

Journal Article:
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  • We report a method to fabricate Nd-Fe-B bonded magnets of complex shape via extrusion-based additive manufacturing (AM), also known as 3D-printing. We have successfully formulated a 3D-printable epoxy-based ink for direct-write AM with anisotropic MQA NdFeB magnet particles that can be deposited at room temperature. The new feedstocks contain up to 40 vol.% MQA anisotropic Nd-Fe-B magnet particles, and they are shown to remain uniformly dispersed in the thermoset matrix throughout the deposition process. Ring, bar, and horseshoe-type 3D magnet structures were printed and cured in air at 100°C without degrading the magnetic properties. Lastly, this study provides a newmore » pathway for fabricating Nd-Fe-B bonded magnets with complex geometry at low temperature, and presents new opportunities for fabricating multifunctional hybrid structures and devices.« less
  • The corrosion behavior of bonded NdFeB permanent magnet materials produced by melt spinning with and without TiC additions has been investigated. Typical anodic polarization experiments in 0.9 M Na{sub 2}SO{sub 4} showed that the addition of 6 a/o TiC resulted in lower corrosion currents and reduced iron dissolution at fixed potential. The role of hydrogen was also investigated by means of galvanostatic charging and discharging experiments (hydrogen absorption and desorption) in 6M KOH which showed that the addition of TiC resulted in a reduction of absorbed hydrogen.
  • Additive manufacturing allows for the production of complex parts with minimum material waste, offering an effective technique for fabricating permanent magnets which frequently involve critical rare earth elements. In this report, we demonstrate a novel method - Big Area Additive Manufacturing (BAAM) - to fabricate isotropic near-net-shape NdFeB bonded magnets with magnetic and mechanical properties comparable or better than those of traditional injection molded magnets. The starting polymer magnet composite pellets consist of 65 vol% isotropic NdFeB powder and 35 vol% polyamide (Nylon-12). The density of the final BAAM magnet product reached 4.8 g/cm3, and the room temperature magnetic propertiesmore » are: intrinsic coercivity Hci = 688.4 kA/m, remanence B r = 0.51 T, and energy product (BH) max = 43.49 kJ/m 3 (5.47 MGOe). In addition, tensile tests performed on four dog-bone shaped specimens yielded an average ultimate tensile strength of 6.60 MPa and an average failure strain of 4.18%. Scanning electron microscopy images of the fracture surfaces indicate that the failure is primarily related to the debonding of the magnetic particles from the polymer binder. As a result, the present method significantly simplifies manufacturing of near-net-shape bonded magnets, enables efficient use of rare earth elements thus contributing towards enriching the supply of critical materials.« less
  • Additive manufacturing (AM) allows for the production of complex parts with minimum material waste, offering an effective technique for fabricating permanent magnets which frequently involve critical rare earth elements. In this report, we demonstrate a novel method - Big Area Additive Manufacturing (BAAM) to fabricate isotropic near-net-shape Nd-Fe-B bonded magnets with magnetic and mechanical properties comparable or better than those of traditional injection molded magnets. The starting polymer magnet composite pellets consist of 65 vol% isotropic Nd-Fe-B powder and 35 vol% polyamide (Nylon-12). The density of the final magnet product reached 4.8 g/cm 3, and the room temperature magnetic propertiesmore » are: Intrinsic coercivity Hci = 8.65 kOe, Remanence Br = 5.07 kG, and energy product (BH) max = 5.47 MGOe (43.50 kJ/m 3). The temperature dependence of the magnetic properties in the final magnet products is similar to that of the starting material, indicating that the BAAM process did not degrade the magnetic properties. In addition, tension tests performed on four dog-bone shaped specimens yielded an average ultimate tensile strength of 6.60 MPa and an average failure strain of 4.18 %. Scanning electron microscopy images indicate that the failure is primarily related to the debonding of the magnetic particles from the polymer binders. Lastly, the present method significantly simplifies manufacturing of near-net-shape bonded magnets, enables efficient use of rare earth elements thus contributing towards enriching the supply of critical materials.« less
  • Magnetic properties and thermal stability were investigated for the MnBi/NdFeB (MnBi = 0, 20, 40, 60, 80, and 100 wt.%) bonded hybrid magnets prepared by spark plasma sintering (SPS) technique. Effect of MnBi content on the magnetic properties of the hybrid magnets was studied. With increasing MnBi content, the coercivity of the MnBi/NdFeB hybrid magnets increases rapidly, while the remanence and maximum energy product drops simultaneously. Thermal stability measurement on MnBi magnet, NdFeB magnet, and the hybrid magnet with 20 wt.% MnBi indicates that both the NdFeB magnet and the MnBi/NdFeB hybrid magnet have a negative temperature coefficient of coercivity,more » while the MnBi magnet has a positive one. The (BH){sub max} of the MnBi/NdFeB magnet (MnBi = 20 wt.%) is 5.71 MGOe at 423 K, which is much higher than 3.67 MGOe of the NdFeB magnet, indicating a remarkable improvement of thermal stability.« less