The unique permanent magnets used in EVs operate at high temperatures of 150 – 200 degrees Celsius. Rare-Earth elements are a constant in the automotive sector that are used to make permanent magnets that produce stronger magnetic fields. Indian scientists have now fabricated an improved low-cost heavy rare earth-free magnet that could boost Electric Vehicle (EV) production in the country in near future.
Scientists from the Centre for Automotive Energy Materials at the International Advanced Research Centre for Powder Metallurgy & New Materials (ARCI) have designed improved rare earth Neodymium Iron Boron (Nd-Fe-B) magnet, which is in high demand for Electric Vehicles and can make them more affordable. The details have been published in Materials Research Letters.
The Nd-Fe-B magnets used in EVs operate at high temperatures of 150 – 200 degrees Celsius and need to exhibit high resistance to demagnetization, a capability that pure Nd-Fe-B magnets do not have. Since its discovery in 1984, the Nd-Fe-B magnets have been one of the most sought-after permanent magnetic materials for many technological applications. It is to be noted that over 90 per cent of EVs use brushless DC (BLDC) motors made up of this rare earth magnet. Globally, researchers are trying to enhance the coercivity (resistance to demagnetisation) of Nd-Fe-B magnets.
Indian scientists have now managed to enhance the coercivity of Niobium (Nb)-containing Nd-Fe-B melt-spun ribbon by using a low melting point alloy, which acts as the source for the non-magnetic element. "The coercivity value of 1 T at 150oC critical for automotive applications achieved in this research published in Materials Research Letter could be a useful strategy to develop magnets without Dysprosium metal or EV applications," the Ministry of Science & Technology, said in a release. The research center has now ventured into setting up of pilot plant for the manufacturing of near-net-shaped Nd-Fe-B magnets and hopes that the strategy will be explored for the magnets manufactured in the pilot plant.
"The new strategy could also be used for commercial production of Nd-Fe-B magnets in India, reducing imports that meet the major requirements of the automotive sector," the ministry added.