Projects / Programmes
Development of rapid radiation-sintering technique for net-shape manufacture of advanced multicomponent Nd-Fe-B permanent magnets with reduced use of critical raw materials
| Code |
Science |
Field |
Subfield |
| 2.04.02 |
Engineering sciences and technologies |
Materials science and technology |
Metallic materials |
| Code |
Science |
Field |
| 2.05 |
Engineering and Technology |
Materials engineering |
Nd-Fe-B permanent magnets, development of a highly innovative radiation-sintering technique, net-shape manufacture, improved magnet’s geometry, improved performance of electrical devices, electrical motors, renewable energy, low-carbon society, rare-earth criticality
Researchers (1)
| no. |
Code |
Name and surname |
Research area |
Role |
Period |
No. of publicationsNo. of publications |
| 1. |
37819 |
PhD Tomaž Tomše |
Materials science and technology |
Head |
2020 - 2023 |
54 |
Organisations (1)
| no. |
Code |
Research organisation |
City |
Registration number |
No. of publicationsNo. of publications |
| 1. |
0106 |
Jožef Stefan Institute |
Ljubljana |
5051606000 |
90,742 |
Abstract
Rare-earth permanent magnets, particularly Nd-Fe-B magnets, are some of the most crucial engineering materials necessary for modern Europe. They are used in a wide range of devices and are essential to the technologies that will facilitate the transition from a fossil-fuel-based energy-and-transportation system to a low-carbon society. Firstly, permanent magnet motors like traction motors of electrical vehicles offer several advantages over induction motors where magnetic flux is generated by current-carrying copper coils, including better energy efficiency, compact size, light weight and high torque. Secondly, some of the alternative electricity-producing technologies like wind-turbine generators also rely on permanent magnets to provide magnetic field. Shape and size of the magnet, the material’s chemical composition and microstructure have been identified as extremely important for energy-conversion applications. The freedom to tailor these parameters is limited intrinsically by the magnet manufacturing method. Polymer-bonded magnets and, more recently, magnets produced by various emerging additive manufacturing techniques, can be produce in intricate shapes, but their overall magnetic performance cannot match the performance of fully-dense sintered magnets manufactured by conventional powder-metallurgy methods. On the other hand, the limitations of the high-temperature sintering approach with regard to the final magnet’s geometry are a major problem for motor designers. In addition, post-sinter machining is required even for basic geometrical forms like rectangular and cylindrical bars. This results in material waste, which is highly undesired, considering that the rare-earth elements are most critical of the EU’s Critical Raw Materials (CRMs). In this Project application, a completely novel approach to the net-shape manufacture of high-performance Nd-Fe-B magnets is proposed. To drastically reduce the sintering times, which is the key to control the final shape of the magnet, as well as to tailor the material’s microstructure, a rapid sintering technique based on the heat transfer by means of intense electromagnetic radiation in vacuum will be developed. A special type of electric resistance furnace, called Spark Plasma Sintering, that enables heating rates several hundred degrees/minute, will be used for this purpose. A part of the work process will focus on the development of a reliable tool for predicting the temperature of the sample. A comprehensive study of the effect of the process parameters on the microstructure and magnetic properties will be performed and the finite element method (FEM) will be used to create a model for simulating the temperature change during heating and predicting the development of temperature gradients in the material. The project will address several topical issues associated with Nd-Fe-B magnets. To improve the resource efficiency, Nd-Fe-B magnetic material with a rare-earth-lean composition will be considered. Reduced sintering times will minimize the grain growth and prevent undesired diffusional processes, boosting the material’s high-temperature performance, which is highly desired for motor applications. Further, magnets containing regions with different chemical compositions (multicomponent magnets) will be prepared, which will minimize the use of alloying additions such as expensive dysprosium and reduce the material costs. Combined with an optimized magnet shape, the properties of such magnets will be beyond the existing state-of-the-art and an important step towards development of the next-generation electrical motors and generators where the design of the device will no longer be constrained by the limited choice of the magnet geometry.
