Iron Nitride magnets: The power of neodymium without the environmental impact

[broli]

If permanent magnets are going to be the power of the future as some believe here then we cannot repeat the same old mistakes of applying ideas before thinking of their impact. Neodymium magnets contain rare earth and conflict minerals that are toxic and concentrated to certain regions of the world.

However there is an alternative that is equal in strength AND orders of magnitude more environmental friendly and cheaper. Iron nitride magnets!

Some companies are already producing these:
https://www.nironmagnetics.com/

There are multiple processes to make these, even a simple cold process, but the two main ingredients are the most abundant on earth, Iron and nitrogen that's it. However I believe it wont take long before the rest of the industrial world catches up, because besides the fact that you feel good about using an "eco friendly" magnet, their source materials are MUCH cheaper and abundant EVERYWHERE on earth, iron can be dug up at the surface and nitrogen is literally everywhere around us in the air, meaning powerful magnets at the fraction of the cost of current Neodymium magnets. And these dont have to be permanent either as further doping with other abundant elements can produce soft cores for power delivery and what not:

https://hackaday.com/2022/09/01/iron-nitrides-powerful-magnets-without-the-rare-earth-elements/#:~:text=To%20make%20iron%20nitride%20magnets,bombarded%20with%20atomic%20nitrogen%20ions.

Lets hope the patent trolls read some history and dont stifle innovation with their greed.

[F6FLT]

Why Don't We Use Fe16N2 Instead of Neodymium Magnets?

https://www.linkedin.com/pulse/magnetics-materials-showdown-why-dont-we-use-iron-nitride-yakunin

Because there's still a long way to go!

[broli]

Why Don't We Use Fe16N2 Instead of Neodymium Magnets?

https://www.linkedin.com/pulse/magnetics-materials-showdown-why-dont-we-use-iron-nitride-yakunin

Because there's still a long way to go!

Poor thermal stability - Fe16N2 decomposes above 200°C, whereas NdFeB can handle 80-220°C depending on grade. Dealbreaker for high-temp uses!

Not sure why the thermal aspect is even an issue if its only 20 degrees off of that of NdFeB. Thermals that high are only an issue in extreme conditions, if you motor is getting that hot you need to hire better engineers.

🔧 Tricky to produce at scale - Making Fe16N2 requires high nitrogen pressure and tight temperature control. Tougher to churn out vs NdFeB.

Well the article I posted also talks about a "cold" process.

Alternatively, iron oxide can be mixed with ammonium nitrate in a planetary ball mill; after a few days of milling at 600 rpm, the stainless steel balls decompose the ammonium nitrate into elemental nitrogen, which diffuses into the iron nanoparticles. The resulting α"-Fe16N2 is then separated by magnet and can be formed into solid shapes. This method seems like it would easily scale up to an industrial process.

Seems to be exactly fit for industrial scales.

💰 Nd more available/affordable than Fe-N compounds. Keeps NdFeB cost down.

This is very confusing. Nd is literally called a RARE earth metal and concentrated in parts of the world that are labeled as "unstable".

🧲 NdFeB simply has higher coercivity and better magnetic stability. Vital where field strength and consistency matters.

This is the only valid remark. However this is still under much ongoing research and who knows what we will discover through the use of doping to modulate the coercivity. But coercivity is highly depended on the application as well. If your application has fields that are continuously opposing your PM then sure but otherwise its not a big deal.

The main problem with any new technology is competition, no one picks it up until the first guy does it and leaves the rest in the dust leaving them playing catchup. Not a fan of Tesla, but they are a good example of this. It only takes one company to show it can be done and make a bigger profit margin to change the industry.

Being able to get your PMs sourced locally is a also big win.

[F6FLT]

@broli

Scarcity does not only concern nature. If it is difficult and expensive to produce, it will remain rare.

The idea that there are great products that we wouldn't use is far-fetched, because as soon as there is money to be made, smart guys and big companies alike are there to exploit the opportunity.
I see two reasons why what appears promising remains useless:
- it's not that promising, the disadvantages have been undervalued or obliterated
- this seems promising but still far from being able to be used as is, it is too early. There is therefore R&D to be done, the cost and risk of failure of which can be dissuasive