Magnetic Contacts

[BuffaloEngineer]

Does anyone have a place they've bought magnetic contacts before (like the power connector on Apple computers)? Is it possible to solder to Neodymium magnets and use them as electrical contacts? Thanks!

 

[jpanhalt]

Surprisingly, there seems to be an answer when I searched on, "can neodymium be soldered."

Check #20 here: https://www.kjmagnetics.com/FAQ.asp#weld

Also, Wikipedia confirms: "Neodymium metal tarnishes slowly in air and it burns readily at about 150 °C to form the neodymium(III) oxide."

You might find some low-melting solder made with indium, gallium, etc. that might work (wetting will be a problem), but why not just use springs for your contacts?

John

Edit: BTW, since neodymium oxidizes so readily in air, you will need to protect any soldered surface. In fact, the surface of your magnet is probably not neodymium, but rather a plating like nickle or chrome. Soldering to nickle is possible, but temperature may still be a problem. So first, find out exactly what your magnets consist of. You may get by with a flash plating of gold or copper followed by low-temp indium-alloy soldering. Some bismuth alloys may also work.

 

[SABorn]

I would not solder onto a neodymium magnet as most are low temp magnets and neodymium magnets DO NOT recover from heat, so you will demagnetise your magnet with heat.

neodymium magnets come with a heat rating like N for 80C and M for 120C and most dont go higher than a M rating.

The higher the rating the greater the price, so most cheaper magnets will have a low temp rating.

What i have done is to solder onto a nickle plated steel washer and just stuck that to the magnet, as they are powerful little suckers and it will contact well.
You could use the metal end from a dead AAA battery to solder onto instead of a washer.

If you use a thicker bit of steel on one side of the magnet and a thinner on the other, the magnet will remain stuck to the thicker piece, and the thinner piece will disconnect from the magnet.

Pete.