New Magnets Could Solve Our Rare-Earth Problems

[www.recumbents.com]

Stronger, lighter magnets could enter the market in the next few years, making more efficient car engines and wind turbines possible. Researchers need the new materials because today's best magnets use rare-earth metals, whose supply is becoming unreliable even as demand grows.

So researchers are now working on new types of nanostructured magnets that would use smaller amounts of rare-earth metals than standard magnets. Many hurdles remain, but GE Global Research hopes to demonstrate new magnet materials within the next two years.

The strongest magnets rely on an alloy of the rare-earth metal neodymium that also includes iron and boron. Magnet makers sometimes add other rare-earth metals, including dysprosium and terbium, to these magnets to improve their properties. Supplies of all three of these rare earths are at risk because of increasing demand and the possibility that China, which produces most of them, will restrict exports.

However, it's not clear if the new magnets will get to market before the demand for rare-earth metals exceeds the supply. The U.S. Department of Energy projects that worldwide production of neodymium oxide, a key ingredient in magnets, will total 30,657 tons in 2015. In one of the DOE's projected scenarios, demand for that metal will be a bit higher than that number in 2015. The DOE's scenarios involve some guesswork, but the most conservative estimate has demand for neodymium exceeding supply by about 2020.

http://www.technologyreview.com/energy/27112/?p1=A1

-Warren.

 

[Biff]

Thats good that they are working on more magnet material, and I hope that the new magnets will have slightly higher operating temperatures, or less performance degredation with temperature.

Its funny that in that little article they suggest that motors would get smaller and lighter with stronger magnets, and although that is true the benefit is rather small. Most of the weight of a motor is in the Iron and Copper. If you consider induction motors aren't that much heavier than PM motors (look at AC propulsion / Tesla Induction motor) and they don't use magnets at all. To reduce weight significantly what we need is a core material that saturates at higher flux densities. The Formula1 Honda KERS motor for example used laminations with more cobalt than normal which increased the saturation point by about 10%, which allowed them to reduce the amount of space used by the laminations, and replace it with copper to increase efficiency.

-ryan

 

[Doctorbass]

I guess that the KERS system in the F1 are using them already... 99% efficiency ( non axial type!) and 60kW for 4' dia by 8" long!

Doc

 

[neuraxon77]

With China nationalizing 11 of their rare earth mines, this can't come soon enough.

 

[Bison_69]

Hello DoctorBass,

Indeed this Kinetic Energy Recovery Systems (KERS) F1 Hybrid is remarquable...

Here is a short explanation of the system...
http://www.youtube.com/watch?v=xAvexjr2ax0

 

[neuraxon77]

If you've ever held a bicycle wheel in your hands and spun it at speed, you'll have felt the resistance to change in direction.
I've often wondered how the flywheel KERS affects the cars change in direction and handling. I'm sure they could use this to their benefit if they wanted to... :wink: After all they use the same principle to stabilise boats for smooth passenger rides!

Here's how it works in microgravity.

[youtube]gdAmEEAiJWo[/youtube]

 

[jdb]

I've often wondered how the flywheel KERS affects the cars change in direction and handling.

The reaction moment of a flywheel is perpendicular to both the applied moment and the axis of rotation. Looking at some of the KERS press pictures, it looks like the axis is front-to-back in the car. So, if the wheels apply a yawing moment to the car, the flywheel's reaction will be a pitching moment. The pitching moment can be modeled as a weight transfer either be front-to-back, or back-to-front. Considering the enormous amounts of downforce on those wheels, I doubt it is significant.

Potentially more problematic is that a pitching moment on the gyro due to rapid changes in grade will induce a yawing reaction moment. In F1, I imagine it isn't too much of a difficulty since the race courses are fairly level (at least, compared to the turning rates).

 

[www.recumbents.com]

Don't they normally use counter rotating flywheels to eliminate some of that effect?

 

[jdb]

Don't they normally use counter rotating flywheels to eliminate some of that effect?

There may be some engineering freedom to design the system as they choose. In that case, why would you want to eliminate the effect? Have a pair of trans-versely mounted asymmetrically rotating flywheels. If the flywheel is transverse (left-to-right), then it transforms a yawing moment into a rolling moment. So, depending on whether you are braking into a left turn or a right turn, you spin up the flywheel that will act like an anti-roll bar for that turn.

Gotta be careful with this sort of dreamy thinking though, without a knowledge of the vehicle's moments of inertia and the momentum of the wheels, we could be talking about very small micro-optimizations. Of course, that's what this racing league is known for, so...

 

[jdb]

Or just one flywheel that alternates in direction (duh, wow, can't believe I missed that one). Obviously the most efficient system would try to return most/all of the flywheel's energy when you come out of the turn.