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Tomography-based digital twins of Nd-Fe-B magnets

Pathway to ultimate coercivity through microstructure optimization

Date:
April 26, 2024
Source:
National Institute for Materials Science, Japan
Summary:
Scientists have succeeded in simulating the magnetization reversal of Nd-Fe-B magnets using large-scale finite element models constructed based on tomographic data obtained by electron microscopy. Such simulations have shed light on microstructural features that hinder the coercivity, which quantifies a magnet's resistance to demagnetization in opposing magnetic fields. New tomography-based models are expected to guide toward the development of sustainable permanent magnets with ultimate performance.
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NIMS has succeeded in simulating the magnetization reversal of Nd-Fe-B magnets using large-scale finite element models constructed based on tomographic data obtained by electron microscopy. Such simulations have shed light on microstructural features that hinder the coercivity, which quantifies a magnet's resistance to demagnetization in opposing magnetic fields. New tomography-based models are expected to guide toward the development of sustainable permanent magnets with ultimate performance.

Green power generation, electric transportation, and other high-tech industries rely heavily on high-performance permanent magnets, among which the Nd-Fe-B magnets are the strongest and most in demand. The coercivity of industrial Nd-Fe-B magnets is far below its physical limit up to now. To resolve this issue, micromagnetic simulations on realistic models of the magnets can be employed.

A new approach to reconstruct the real microstructure of ultrafine-grained Nd-Fe-B magnets in large-scale models is proposed in this research. Specifically, the tomographic data from a series of 2D images obtained by scanning electron microscopy (SEM) in combination with consistent focused ion beam (FIB) polishing can be converted into a high-quality 3D finite element model. This tomography-based approach is universal and can be applied to other polycrystalline materials addressing a wide range of materials science problems.

Micromagnetic simulations on the tomography-based models reproduced the coercivity of ultrafine-grained Nd-Fe-B magnets and explained its mechanism. The microstructural features relevant to the coercivity and nucleation of magnetization reversal were revealed. Thus, the developed model can be considered as a digital twin of Nd-Fe-B magnets -- a virtual representation of an object designed to reflect its physics accurately.

The proposed digital twins of the Nd-Fe-B magnets are precise enough in reproducing both the microstructure and magnetic properties that can be implemented for the inverse problem in designing on-demand high-performance permanent magnets. For instance, when researchers input the magnetic properties required for a specific application (e.g., traction or variable magnetic force motor), a data-driven research pipeline with integrated digital twins will be able to propose the optimal composition, processing conditions, and microstructure of the magnet for that application, significantly reducing development time.


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Materials provided by National Institute for Materials Science, Japan. Note: Content may be edited for style and length.


Journal Reference:

  1. Anton Bolyachkin, Ekaterina Dengina, Nikita Kulesh, Xin Tang, Hossein Sepehri-Amin, Tadakatsu Ohkubo, Kazuhiro Hono. Tomography-based digital twin of Nd-Fe-B permanent magnets. npj Computational Materials, 2024; 10 (1) DOI: 10.1038/s41524-024-01218-5

Cite This Page:

National Institute for Materials Science, Japan. "Tomography-based digital twins of Nd-Fe-B magnets." ScienceDaily. ScienceDaily, 26 April 2024. <www.sciencedaily.com/releases/2024/04/240426165201.htm>.
National Institute for Materials Science, Japan. (2024, April 26). Tomography-based digital twins of Nd-Fe-B magnets. ScienceDaily. Retrieved May 28, 2024 from www.sciencedaily.com/releases/2024/04/240426165201.htm
National Institute for Materials Science, Japan. "Tomography-based digital twins of Nd-Fe-B magnets." ScienceDaily. www.sciencedaily.com/releases/2024/04/240426165201.htm (accessed May 28, 2024).

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