X-MINING X-TALK Vol.6 【Part 2】 Magnetic Material Applications Such as EV Motors,
and the Potential of Samarium-Iron-Nitrogen Magnetic Materials

When it comes to automotive motors, one automobile is equipped with about 100 motors, including the drive motor, which is the largest. Because strong magnets realize smaller, lighter, and more efficient motors, neodymium magnets are used in many motors. In some applications, a neodymium magnet can be replaced with an SFN magnet, while in others, such replacement is impossible or not preferable. The market configuration will change if more motors use an SFN magnet in place of a neodymium magnet. As we see the future supply–demand balance, such a change is certain to be good for the earth.

It is true that the neodymium magnets used in drive motors are sintered magnets and that the bonded magnet products we supply cannot substitute for them. SFN magnets, which are molded with resins, are considerably different in performance. Of course, we will proceed with our research and development efforts to catch up with and surpass neodymium magnets. For applications where a current SFN magnet can substitute, we would be happy to supply our products. We may need to ask customers to make a minor change or come up with a solution to adopt our products. We hope to build business cooperation while promoting the products through this X-MINING website.

In addition to the difference in the included rare earth elements, namely, neodymium versus samarium, neodymium bonded magnets are molded by compression, while SFN magnets are molded by injection. Injection-molded SFN magnets have a lower density, enabling motor miniaturization and weight reduction. Currently, all products are being downsized across the market, thus small and lightweight motors are in high demand. SFN is useful in such applications.

As we proceed with our research and development efforts and become able to produce sintered SFN magnets, some of the neodymium magnets in the drive motor can be replaced. We believe that this will realize a more stable supply of rare earths and price stabilization in the market.

Concerning EVs, tare weight reduction is an important issue, and this product may have potential in this respect. When it comes to EVs, the problem of battery charging points has been pointed out. This problem is related to the battery. The charging unit is associated with the performance of the drive motor. It looks to me that all the related units and materials together are required to improve their own functions.

Another fact to be noted is that samarium magnets are more resistant to rust than other rare earth magnets. As an example, most neodymium magnets are coated because they rust easily, but SFN magnets can be used without coating, depending on the application. As the coating material, a highly volatile organic solvent is used, which may be unfriendly to the environment. SFN magnets are more environment-friendly in this sense.

Another type of magnet including samarium is samarium cobalt magnet. Samarium cobalt magnets are resistant to rust and highly heat resistant. However, cobalt (Co) is a minor metal, whose output is limited with an unstable price. The use of samarium cobalt magnets is extremely limited in the market.
In this sense, SFN magnets include only samarium as a rare earth. I would say that the risk of a price surge for this material is low.

Samarium cobalt

Concerning safety to the human body, rare earth ore includes radioactive substances, but after these are separated, the elements included in magnet materials are basically safe. It is important to control the radioactive substances and residues properly at the time of removal.

In this sense, the problem with rare earths is not so much the refined rare earths themselves but rather the locations where the ores are mined.

That’s right. Rare earth elements lie across the world, at various locations, as natural resources. The sites that can produce them while carefully controlling the radioactive substances are limited. This is one of the reasons why the bulk of the world’s rare earths are produced in China. However, such a heavy dependence on that country risks reducing stability in terms of supply and pricing. It would be better if supplier sites were more dispersed. Recently, rare earth production in the U.S. and Australia has been increasing. I expect that such diversification will make more progress.

I see a good business opportunity with SFN now. This is not limited to magnet materials, but also developing a solution to the insufficient supply of natural resources. We would like to contribute to material supply according to customer needs, while listening to customers’ firsthand requests at production sites. Because many companies procure and develop materials on their own, supplying a pure magnetic material may be a possible approach. Especially in Europe, the EV market is certain to produce demand for this product, and we hope to make more efforts in this area.

For example, as has been mentioned, when coating is necessary, the manufacturer may incur a significant cost due to this relatively minor process. It may be possible to promote SFN, pointing out that if SFN magnetic material is used, coating will not be required. Digging out customer needs will reveal more business opportunities, as opposed to presenting possible application ideas from our side. We would like to increase the market acceptance of the materials while locating customer needs.

We also have many application ideas where SFN material can be used. Concerning the automobiles that we have talked about, it is necessary to cool down the motors. When the battery is being charged or discharged, it heats up. The battery needs to be cooled down. For the cooling fans used for these applications, SFN may be useful, because it can be molded into complicated shapes. In response to ideas we provide, manufacturers may raise various issues. For us it will be important to listen to their feedback.
What is most difficult is communicating the advantages of the materials to potential users, providing technical assistance, increasing our presence at the customer, and paving the way for the material to be selected.

I agree. We hope to grasp potential opportunities agilely and move forward to solve the challenges.

We often receive this question — “Why does Sumitomo Metal Mining produce these materials?” We would like to present effective solutions in the case of resource shortages that are expected in the future. We hope to move ahead with the development of materials that will contribute to solving problems in society, in cooperation with players in various fields.