Next Article in Journal
A Review of Methods for Increasing the Durability of Hot Forging Tools
Previous Article in Journal
Trans-Scale Progressive Failure Analysis Methodology for Composite Materials Incorporating Interfacial Phase Effect
Previous Article in Special Issue
Microstructural Characterisation of Bi-Ag-Ti Solder Alloy and Evaluation of Wettability on Ceramic and Composite Substrates Joined via Indirect Electron Beam Heating in Vacuum
 
 
Font Type:
Arial Georgia Verdana
Font Size:
Aa Aa Aa
Line Spacing:
Column Width:
Background:
This is an early access version, the complete PDF, HTML, and XML versions will be available soon.
Article

Production of Anisotropic NdFeB Permanent Magnets with In Situ Magnetic Particle Alignment Using Powder Extrusion

1
Institute for Precious and Technology Metals, Pforzheim University, Tiefenbronner Str. 65, 75175 Pforzheim, Germany
2
Department of Polymer Engineering and Science, Institute of Polymer Processing, Montanuniversitaet Leoben, Otto Gloeckel-Straße 2, 8700 Leoben, Austria
3
Research and Innovation Service, Montanuniversitaet Leoben, Franz-Josef-Strasse 18, 8700 Leoben, Austria
4
Faculty of Physics, University of Vienna, Boltzmanngasse 1, 1090 Vienna, Austria
*
Authors to whom correspondence should be addressed.
Materials 2025, 18(15), 3668; https://doi.org/10.3390/ma18153668
Submission received: 24 June 2025 / Revised: 25 July 2025 / Accepted: 31 July 2025 / Published: 4 August 2025
(This article belongs to the Special Issue Advanced Materials and Processing Technologies)

Abstract

This study investigates the sustainable production of NdFeB permanent magnets using powder extrusion molding (PEM) with in situ magnetic alignment, utilizing recycled powder from an end-of-life (Eol) wind turbine magnet obtained via hydrogen processing of magnetic scrap (HPMS). Finite Element Method (FEM) simulations were conducted to design and optimize alignment tool geometries and magnetic field parameters. A key challenge in the PEM process is achieving effective particle alignment while the continuous strand moves through the magnetic field during extrusion. To address this, extrusion experiments were performed using three different alignment tool geometries and varying magnetic field strengths to determine the optimal configuration for particle alignment. The experimental results demonstrate a high degree of alignment (Br/Js = 0.95), exceeding the values obtained with PEM without an external magnetic field (0.78). The study confirms that optimizing the alignment tool geometry and applying sufficiently strong magnetic fields during extrusion enable the production of anisotropic NdFeB permanent magnets without post-machining, providing a scalable route for permanent magnet recycling and manufacturing. Moreover, PEM with in situ magnetic particle alignment allows for the continuous fabrication of near-net-shape strands with customizable cross-sections, making it a scalable approach for permanent magnet recycling and industrial manufacturing.
Keywords: powder extrusion molding (PEM); metal injection molding (MIM); anisotropic NdFeB permanent magnets; recycling of end-of-life (Eol)-magnets powder extrusion molding (PEM); metal injection molding (MIM); anisotropic NdFeB permanent magnets; recycling of end-of-life (Eol)-magnets

Share and Cite

MDPI and ACS Style

Rathfelder, S.; Schuschnigg, S.; Kukla, C.; Holzer, C.; Suess, D.; Burkhardt, C. Production of Anisotropic NdFeB Permanent Magnets with In Situ Magnetic Particle Alignment Using Powder Extrusion. Materials 2025, 18, 3668. https://doi.org/10.3390/ma18153668

AMA Style

Rathfelder S, Schuschnigg S, Kukla C, Holzer C, Suess D, Burkhardt C. Production of Anisotropic NdFeB Permanent Magnets with In Situ Magnetic Particle Alignment Using Powder Extrusion. Materials. 2025; 18(15):3668. https://doi.org/10.3390/ma18153668

Chicago/Turabian Style

Rathfelder, Stefan, Stephan Schuschnigg, Christian Kukla, Clemens Holzer, Dieter Suess, and Carlo Burkhardt. 2025. "Production of Anisotropic NdFeB Permanent Magnets with In Situ Magnetic Particle Alignment Using Powder Extrusion" Materials 18, no. 15: 3668. https://doi.org/10.3390/ma18153668

APA Style

Rathfelder, S., Schuschnigg, S., Kukla, C., Holzer, C., Suess, D., & Burkhardt, C. (2025). Production of Anisotropic NdFeB Permanent Magnets with In Situ Magnetic Particle Alignment Using Powder Extrusion. Materials, 18(15), 3668. https://doi.org/10.3390/ma18153668

Note that from the first issue of 2016, this journal uses article numbers instead of page numbers. See further details here.

Article Metrics

Article metric data becomes available approximately 24 hours after publication online.
Back to TopTop