Since 2000, we have witnessed an evolution in the direction of motors and generators fitted with permanent magnets in the rotor (usually referred to as Permanent Magnet Synchronous Machines PMSM). In any motor, interaction of the magnetic fields of the rotor and the stator create the rotational force that drives the machine.
Permanent magnets generate a constant magnetic field and thus generate a flux by design. As a result, the power density and dynamic performance of PMSM machines are higher compared to induction machines or electrically excited machines, where this magnetic field must be created (directly or indirectly) via an electrical current. And these magnets keep their magnetism. Even after 25 years of use, there is no measurable demagnetisation on the magnets.
Also, Magnax machines (motors or generators) use neodymium magnets (NdFeB ). However, thanks to the axial flux topology, which is significantly more effective in terms of flux density than the traditional radial flux topology, our machines require more than 50% less PM material to generate the same torque. Or in other words; Suppose that the world starts using Magnax axial flux motors and generators instead of traditional permanent magnet motors and generators (which are based on radial flux), the demand for permanent magnets would significantly drop!
And this might be necessary since the demand for Neodymium magnets is expected to increase significantly. Especially in the near future when the automotive industry will convert ICE-based vehicles to EVs (electric vehicles).
Tesla's shift to a motor using neodymium in its Model 3 Long Range car seems to add even more pressure on already strained supplies of a rare earth metal that had for years been shunned because of an export ban by top producer China. So it's only understandable that some of these EV suppliers are afraid that the supply of the magnets will become even more difficult in the near future.
However, companies like Tesla would not switch to PM machines, if they were expecting huge problems around the future supply of these magnets. Despite their name, rare earth (RE) are found in many places around the world. But the process of extraction is difficult and expensive, as it requires separating multiple different metals from a single deposit. Until 2011, mainly Chinese companies have been investing in mines to extract the materials, which resulted in a Chinese monopoly on the magnet material market.
So, the problem is not that the amount of RE (rare earth) materials is limited because our earth has enormous quantities of these materials available. It was the shortage of mines and the fact that most of them were located in China that resulted in the 2011 RE crisis. However, this instant price increase accelerated the development of rare earths projects outside China, with projects in Australia, Russia, Brazil, Canada, Burundi and Tanzania set to enter production by 2027 or sooner.
And already today, several companies produce rare earth metals outside China, including London-listed Rainbow Rare Earths, Canada-listed Namibia Rare Earths and Australia's Spectrum Rare Earths and the list is growing quickly. So wherever there is a significant demand, new companies pop up to meet the demand with new supply.
The potential supply risks of the heavy rare earth elements is mainly problematic for specific RE materials in the magnets such as Dy (Dysprosium), which is currently used to realize the high coercivity of the magnets at their operating temperatures. Realization of high coercivity at high temperatures without using the heavy rare earth elements is, therefore, strongly required for a sustainable growth of these application markets and, ultimately, for sustaining the green earth.
And that's where significant improvements are currently made for the production of magnet metals which are partly or entirely RE free. And they will be able to meet the specs of the current magnets.
Already in 2015, Toshiba pushished a press release that they succeeded in creating FeNe magnets without RE materials. And there are more innovations on the horizon so we can only expect that the "China problem" is a temporary one.