Last updated on July 27th, 2023 at 06:23 pm
Heavy rare earth-free high Nd-Fe-B magnets, which are in high demand for Electric Vehicles, have been fabricated by scientists to make them more affordable.
Brushless DC (BLDC) motors made up of rare earth Neodymium Iron Boron (Nd-Fe-B) magnets are used in more than 90% of EVs. The Nd-Fe-B magnet has been sought-after for many applications since its discovery in 1984 due to its exceptional combination of magnetic properties.
Nd-Fe-B magnets used in EVs need to exhibit high resistance to demagnetization at high temperatures of 150 – 200oC, a capability that pure Nd-Fe-B magnets do not have.
As a result, Dysprosium (Dy) metal is added as an alloy to improve the resistance to demagnetization. Researchers all over the world are trying to find ways to make Nd-Fe-B magnets more resistant to demagnetization without having to use expensive Dy.
“Non-magnetic” elements are introduced into the region between the grains of the Nd-Fe-B magnet through suitable heat treatments to enhance coercivity.
Recently, scientists from the Center for Automotive Energy Materials at the International Advanced Research Center for Powder Metallurgy and New Materials (ARCI), an autonomous research and development center of the Department of Science and Technology (DST), Govt.
The Government of India has enhanced the coercivity of Niobium (Nb)-containing Nd-Fe-B melt-spun ribbons by the Grain Boundary Diffusion Process (GBDP) using the low melting point alloy of Nd70Cu30 as a source of “non-magnetic” Works in element.
They have reported restricted grain growth during grain boundary diffusion due to the precipitation of Nb, which facilitates the enrichment of copper (Cu) at the grain boundaries to enhance the resistance to demagnetization of Nd–Fe–B powders.
In this research published in Materials Research Letters, a coercive value of 1 T at 150oC, critical for automotive applications, could be a useful strategy to develop magnets without Dy for EV applications.
ARCI has undertaken to set up a pilot plant for the manufacture of near pure size Nd-Fe-B magnets through a flagship project funded by the Science and Engineering Research Board (SERB) in line with the Atmanirbhar Bharat Mission of the Government of India, and The above strategy will be explored for magnets manufactured in the pilot plant.
The new strategy can also be used for commercial production of Nd-Fe-B magnets in India, thereby reducing imports that meet the key requirements of the automotive sector.
