Mischmetal-Fe-B nanoflakes for a new class of anisotropic permanent magnets

PROJECT TITLE: Mischmetal-Fe-B nanoflakes for a new class of anisotropic permanent magnets

PROJECT ACRONYM: NanoCAMP

FUNDING SOURCE: Executive Agency for Higher Education, Research, Development and Innovation Funding (UEFISCDI) within PNCDI III- Program 1

PROJECT CODE: PN-III-P1-1.1-TE-2021-0976

CONTRACT NUMBER: TE 129

PROJECT DURATION: 24 months (02.05.2022 – 30.04.2024)

PROJECT BUDGET: 450.000 RON

PROJECT SUMMARY:

Permanent magnets are critical components for modern life, being used from home applications to robotics, green energy, and military applications. The most powerful and widely used magnets available today are NdFeB magnets with additions of Dy, Pr, Tb. Elements like Nd, Dy, and Pr being certificated as critical materials due to the higher price and less abundance.

In this context, the current project proposes the replacement of critical rare earth such as Nd, Dy, Pr in the RE-Fe-B system with mischmetal (MM) to develop a new type of nanocomposite magnets based on anisotropic nanoflakes (MM2Fe14B). The motivation for this choice comes from the fact that MM is a natural mixture of Nd, Pr, La, and Ce and does not require separation. Therefore, the elimination of polluting processes of separation and purification of rare earth leads to a significant reduction of costs and waste. However, the total replacement of Nd and Dy with MM leads to a decrease in Curie temperature, saturation magnetization, and thus the energy product (BH)max. The project also comes up with solutions to remove these shortcomings by nitriding nanoflakes (interstitial penetration of nitrogen atoms into the cell structure of the MM2Fe14B phase) and by switching between the magnetic phases of the nanocomposite magnet MM2Fe14B/αFe. Thus we can say that the resulting magnets will develop magnetic performance capable of filling the gap between NdFeB and hard ferrites.

PROJECT OBJECTIVE

General objective: Development of a new generation of magnetic materials for permanent magnets by replacing critical rare earths (RE) such as Nd, Dy, Pr in the RE-Fe-B system with mischmetal (MM) to develop a new type of nanocomposite magnets based on anisotropic nanoflakes ( MM2Fe14B).
Specific objective 1: Preparation of ribbons with optimized composition and establishing parameters of annealing treatment (time, temperature) and/or magnetic field assisted annealing, in order to control the formation of the hard magnetic phase.
Specific objective 2: Determination of the optimal parameters for surfactant assisted milling of the ribbons based on MM-Fe-B in order to obtain nanoflakes; mixing and establishing the optimal ratio of hard phase (based on MM-Fe-B) / soft phase (αFe) and obtaining composite powders.
Specific objective 3: Identification and optimization of SPS compaction factors/ alignment (time, pressure, temperature, magnetic field) with effect on magnetic characteristics of the final MM2Fe14B / αFe samples.

EXPECTED RESULTS:

Obtaining:
- MM-Fe-B-based ribbons, with nanocrystalline structure,
- Nanocomposite mixed powders based on MM2Fe14B/αFe,
- Nanocomposite permanent magnets in form of discs with value of the energy product (BH)max above 15MGOe,
- 3 communications to a national/international conference,
- 3 articles sent to a journal Q1or Q2 category

Achieved results:
Publications:
1) M. Lostun, M. Grigoraș, G. Ababei, L.C. Răcilă, T. Roman, G. Stoian, and N. Lupu“
”Effect of nonmagnetic Hf addition on magnetic properties of melt-spun Misch Metal-Fe-B ribbons” under review to ISI-ranked journal “ Journal of Rare Earths” Q2.
Conference presentations:
1) “ Effect of nonmagnetic Hf addition on magnetic properties melt-spun Misch Metal-Fe-B ribbons” M. Lostun, M. Grigoraș, G. Ababei, L.C. Răcilă, T. Roman, and N. Lupu.
13th Joint European Magnetic Symposia (JEMS-2023) 27th Aug-1st Sep, 2023 Madrid, Spain.
2) ”Tuning the hard magnetic properties of melt-spun Misch Metal-Fe-Hf-B ribbons by heat treatment” M. Lostun, M. Grigoraș, G. Ababei, L.C. Răcilă, T. Roman, and N. Lupu.
27th International Workshop On Rare Earth And Future Permanent Magnets And TheirApplications-REPM-2023, 3rd-7th September, 2023, Birmingham, UK.

2022 Activity Report Summary
2023 Activity Report Summary

Project Coordinator:

Mihaela Grigoraș (Lostun), Ph.D
National Institute of R&D for Technical Physics, NIRDTP Iași
47 Mangeron Boulevard, 700050 Iași, Romania
Email: mlostun@phys-iasi.ro
Tel.: +40 232 430680 (int 213)
Fax: +40 232 231132