Magnet Destruction

Nd magnets are sintered and usually coated with some kind of polymer or Ni-based shell.

I have used epoxy-coated ones before. Mfgr of something like that might have info on compatibility with H2.

Thanks!

Thanks for that, I'll contact them to see if they have an equivalent magnet to survive in hydrogen.

May be James Stewart has some bright explanation on this.

Found this...

http://www.osti.gov/scitech/servlets/purl/933032/

I have a lot of neodymium magnets plated with nickel. They're fine when they're new, but after a while the nickel plating comes off. I have some gold plated ones that are still in very good condition, although they have not seen any hard use. They are more expensive.

Neodymium Iron Boron magnets are very susceptible to corrosion and need to be coated with some material.

Here is some information on some of the common coatings. I don't know how these coatings stand up against hydrogen.

Thanks, good information. Gold is OK in vacuum although I would have to consider what might be trapped under the coating within the magnet structure. Price is not a problem, these finished devices will not be cheap.

I m really guessing here, but a sintered metal is basically full of tiny holes.

With a vacuum, even when plated, you might damage the plating as the air inside expands and contracts as the vacuum is applied and stopped, applied and stopped. Maybe damaging the plating over a time period....

If I was trying to make them gas proof, I would look at something like a high pressure "filling" of those gaps with a thin liquid epoxy resin or similar. That way, no gas to expand, though I am unaware of how hard epoxy reacts under a vacuum, there may be something better around....

Then clean off the outside and plate.

Though there may be no need to plate at all if a thin coating exists over the metal... but it would still need to be tested and checked.

Just a thought...

Something like that could work, there are impregnations which are OK in vacuum.