Handling Indium Wire – 5 Things You Need to Know
Those of you who have experience with indium metal know that it can be a little tricky to handle, and for you readers who are new to the material: we are going to explain what you should expect when working with indium for the first time.
Pure indium has a few unique properties that make it different to handle than many other metal sealing materials. Wire especially, because of its form, can turn into a tangled mess unless you know these 5 properties of the material as they relate to handling wire:
It is soft - REALLY soft!
Indium is much softer than lead, it’s the softest metal that you can actually handle. (And it retains its softness at cryogenic temperatures) It makes a great gasket material because it is compliant with the surfaces it is sandwiched between, but it also makes it a little tricky to handle. As you are filling a flange groove with wire, be aware that pulling on indium can easily stretch it. This would neck-down the diameter of the wire. Be careful with the material, and you should have no problems with application. Sometimes the softness does make working with longer sections of wire tricky, so keep it on the spool as much as possible.
It sticks to itself
I’m going to guess at some point you may have had two pieces of tape stick together. Depending on the type of tape (and how much you have left), sometimes it’s best to just use a new piece, because those two joined pieces are NOT coming apart. A similar situation can occur with indium, since it cold welds to itself. Do your best to keep it separated from itself: the more clean and pure the wire is, the more likely it is to stick to itself. We ship our wire with a barrier layer between wraps so it doesn’t stick during shipment. The wire we provide is 99.995% to 99.999% pure indium – which (is great for sealing applications but) makes it likely to cold weld to itself. If this does happen, no worries, just keep it along with your used indium and we can recycle it for you.
It will leave black oxides behind
We advise you use nitrile gloves when handling pure indium. This will keep your hands clean, and it will keep the indium surface clean. Oils from your hands can outgas in a vacuum application. As far as the oxide is concerned, indium oxide is self-limiting. That is, it grows to a thin film on the surface of the wire and then stops growing. It can be cleaned by using alcohol, or removed completely (though only temporarily if exposed to air) by submerging the indium in 10% HCl for 5 minutes and then thoroughly rinsing the wire with DI water.
It is safe to handle
Although it is best practice to use gloves to keep the material and your hands clean, indium can be handled like most other common metals at room temperature. If you have any concerns, just let us know and we can send you a Safety Data Sheet with your material.
It can be recycled
Or better yet: it SHOULD be recycled. Why throw away this amazing material when you can have it made into new product for yourself? Contact us when you are ready to return the indium and we can process it into fresh wire for future use. You can contact us for new indium or recycling at (855) 246-3486 or send us an email to learn more at sales@indiumwire.com
