Magnet Type for Heat Engine: Alnico or Rare Earth?

  • Thread starter Thread starter TESL@
  • Start date Start date
  • Tags Tags
    Magnet Type
AI Thread Summary
The discussion focuses on selecting the right type of permanent magnet for a new heat engine design, emphasizing the need for shock resistance, strength-to-weight ratio, and high Curie temperature. Alnico magnets are initially considered due to their robustness and temperature resistance, but there is curiosity about the viability of rare-earth magnets, particularly neodymium. Concerns are raised about the fragility of magnets at high RPMs, especially in brushless model aircraft motors, and the potential hazards of using carbon fiber. The idea of using a stronger metal for coating neodymium magnets is proposed, with suggestions of steel or gold plating. Ultimately, there is uncertainty about the effectiveness of any coating in preventing magnet shattering under extreme conditions.
TESL@
Messages
122
Reaction score
8
I'm planning to use some permanent magnets in a new kind of heat engine I designed. The properties I am seeking are:

- Resistance to shockwaves and high acceleration,
- Relatively great strength/weight ratio,
- and relatively high curie temperature.

After a quick research, I think the best fit type of magnet would be "Alnico"s which are robust and temperature resistant. However I need to know if there are any strong rare-earth magnets that do not break easily and suitable for this job,

Thank you.
 
Physics news on Phys.org
Some brushless model aircraft electric motors rotate at very high rpm. The rotor is wrapped with carbon fibre to help keep the magnets attached.
 
  • Like
Likes 1 person
Wrapping with carbon fiber will not decrease the force applied on the magnets so they will shatter anyway. Also, carbon fiber is flammable.

...but you gave me an idea that neodymium magnets are coated by nickel. Can I instead use a stronger metal to contain the powder?

edit: Any type of plating is possible, so I decided to coat with steel or gold. "https://www.kjmagnetics.com/neomaginfo.asp"
 
Last edited by a moderator:
If wrapping with carbon fibre doesn't help then I've no idea how plating with gold or steel helps? Guess I totally misunderstand what you are trying to do.
 
Nope, I'm wrong, nothing will help. How do we close the thread?
 
Back
Top