Με την αύξηση της παραγωγής των ηλεκτρικών και υβριδικών αυτοκινήτων, έχει αυξηθεί παράλληλα και η ζήτηση για βαρέα σπάνια μέταλλα, που απαιτούνται για την λειτουργία των ηλεκτροκινητήρων, όπως είναι το τέρβιο και το δυσπρόσιο.
Η Honda με σκοπό να μειώσει την εξάρτησή της από τα σπάνια αυτά μέταλλα, εργάστηκε με έναν ιαπωνικό προμηθευτή μετάλλων, την Daido Steel Co., με τον οποίο ανέπτυξαν μια διαδικασία και πλέον δεν απαιτείται η χρήση των μετάλλων αυτών. Η νέα διαδικασία χρησιμοποιεί μια μέθοδο που καλείται «θερμής παραμόρφωσης» και απαιτεί ένα άλλο μέταλλο, που ονομάζεται νεοδύμιο και πρόκειται να μειώσει αρκετά το κόστος παραγωγής. Το πρώτο αυτοκίνητο που αναμένεται να χρησιμοποιεί τους νέους κινητήρες, θα είναι το Honda Freed, ένα minivan, και αναμένεται να διατεθεί στην ιαπωνική αγορά στο τέλος αυτού του χρόνου. Το αυτοκίνητο κυκλοφορεί στην Ιαπωνία με κινητήρα αερίου ήδη από το 2008, ενώ από το 2011 κυκλοφορεί και η υβριδική του έκδοση με κατανάλωση 5,5 λίτρα/100 χλμ.
Η κίνηση αυτή έγινε από την Honda, καθώς προβλέπεται αύξηση της παραγωγής των ηλεκτρικών και υβριδικών οχημάτων μέσα στα επόμενα χρόνια. Με αυτό τον τρόπο, εκτιμά ότι το κόστος παραγωγής των ηλεκτρομαγνητών για τους κινητήρες θα μειωθεί κατά 10%, ενώ το βάρος τους θα πέσει κατά 8%. Πέραν αυτού όμως, θα ανεξαρτητοποιήσει τις ανάγκες της από την Κίνα, που μέχρι τώρα είναι ο βασικός προμηθευτής των πρώτων μετάλλων, καθώς το νεοδύμιο, που θα χρησιμοποιείται πλέον, πέρα από την Κίνα, βρίσκεται ακόμη στην Αυστραλία και την Β. Αμερική.
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Daido Steel and Honda Adopt World’s First Hybrid Vehicle Motor Magnet Free of Heavy Rare Earth Elements
– Honda Freed, on sale this fall, will be the first hybrid vehicle to adopt new magnet –
TOKYO, Japan, July 12, 2016 – Daido Steel Co., Ltd. and Honda Motor Co., Ltd. became the world’s first companies to achieve practical application of a hot deformed neodymium magnet containing no heavy rare earth*1 and yet with high heat resistance properties and high magnetic performance required for the use in the driving motor of a hybrid vehicle. This heavy rare earth-free hot deformed neodymium magnet will be applied first to the all-new Honda FREED, scheduled to go on sale this fall.
[Background]
Neodymium magnets have the highest magnetic force among all magnets in the world and are being used for the drive motors of electric vehicles including hybrid vehicles, and therefore demand for neodymium magnets are expected to grow exponentially in the future.
For use in the drive motors of electric vehicles, neodymium magnets must have high heat resistance properties as they are used in a high temperature environment. Adding heavy rare earth (dysprosium and/or terbium) to the neodymium magnets has been a conventional method to secure such high heat resistance.
However, major deposits of heavy rare earth elements are unevenly around the world, and also are categorized as rare metals; thus, the use of heavy rare earth carries risks from the perspectives of stable procurement and material costs. Therefore, a reduction in the use of heavy rare earth elements has been one of the major challenges needing to be addressed in order to use neodymium magnets for the drive motors of hybrid vehicles.
[New development]
Daido Electronics Co., Ltd., a wholly owned subsidiary of Daido Steel, has been mass-producing neodymium magnets using the hot deformation method, which is different from the typical sintering production method for neodymium magnets. The hot deformation method is a technology that enables nanometer-scale crystal grains to be well-aligned in order to realize a fine crystal grain structure that is approximately ten times smaller than that of a sintered magnet, which makes it possible to produce magnets with greater heat resistance properties.
This time, Daido Steel and Honda jointly developed new neodymium magnets while Daido Steel further evolved its hot deformation technologies and Honda leveraged its experience in development of drive motors and revised the shape of the magnet. Through these joint development efforts, the two companies achieved, for the first time in the world, a practical application of a neodymium magnet which contains absolutely no heavy rare earth yet has high heat resistance and high magnetic performance suitable for use in the drive motor of hybrid vehicles.
Moreover, Honda designed a new motor which accommodates this new magnet. In addition to the shape of the magnet, Honda revised the shape of the rotor to optimize the flow of the magnetic flux of the magnet. As a result, the hot deformed neodymium magnet that contains absolutely no heavy rare earth became usable for the drive motor of a hybrid vehicle, demonstrating torque, output and heat resistance performance equivalent to those of a motor that uses the conventional type of magnet.
[Benefit of this technology]
Adoption of this technology enables a break from the constraints associated with heavy rare earth, which had been one of the challenges to expanding the use of neodymium magnets. This technology will make it possible to avoid resource-related risks and diversify channels of procurement.
[Next steps]
＜Honda＞
Honda will first apply this hot deformed neodymium magnet with absolutely no heavy rare earth to the Honda SPORT HYBRID i-DCD*2, a hybrid system Honda will adopt for the all-new FREED scheduled to go on sale this fall. Honda will continue expanding application of this technology to new models in the future.
＜Daido Steel＞
With the newly-developed hot deformed neodymium magnet, Daido Steel will make a new entry into the market for magnets used for drive motors of hybrid vehicles, which has been basically monopolized by sintered neodymium magnets. Starting next month, August 2016, Daido Electronics will begin the mass-production and shipment of this magnet using a new production line that the company built in its factory (located in Nakatsugawa City in Gifu Prefecture in Japan) using a subsidy*3 received from the Japanese Ministry of Economy, Trade and Industry (METI).
Moreover, Daido Steel will continue pursuing the development of heavy rare earth-free magnets with further improved properties.
Furthermore, Daido Steel has been procuring magnetic powder, the raw material for magnets, from Magnequench International Inc. (located in Toronto, Ontario, Canada), and Daido Steel will work together with Magnequench to develop new types of raw magnetic powders for the purpose of realizing enhanced magnetic properties.
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