Sciencemadness Discussion Board

Metallic glue

Morgan - 28-1-2016 at 14:55

Some indium and gallium application ...
http://www.northeastern.edu/news/2016/01/researchers-metalli...

chemrox - 28-1-2016 at 17:03

I tweeted it.

Theoretic - 29-1-2016 at 08:40

"...infinitesimally small rods with metal cores that we have coated with the ele­ment indium on one side and galium on the other. These coated rods are arranged along a sub­strate..."

it's not made very clear how this is accomplished, and if it's a process as easy and facile as the word 'glue' implies.
looking at the title at first, I thought it might have been a metal powder-metal liquid reaction, like a dental amalgam.

[Edited on 29-1-2016 by Theoretic]

unionised - 29-1-2016 at 11:06

https://en.wikipedia.org/wiki/Liquid_metal_embrittlement

Theoretic - 30-1-2016 at 07:42

Quote: Originally posted by unionised  
https://en.wikipedia.org/wiki/Liquid_metal_embrittlement

don't just post a bare link! give a quote, and say something.
although, if you had read even the first paragraph, you'd know there are exceptions; and in any case how does one think the metal would be embrittled in the short time the mix takes to solidify.

unionised - 30-1-2016 at 10:55

OK, but the comment I would have made was "are you aware of liquid metal embrittlement?".
I rather suspect that most people would have got the gist of that from the wiki page's name.

I know there are exceptions. Gallium is noted for not being one of them (well- not always- I will come back to that).

The exception the mention is that, while you normally need the material to be under load to get it to embrittle, with at least one gallium alloy, it embrittles even more easily than that. Did you read it before telling me I should read it?


The gallium indium phase diagram shows a minimum melting point- the eutectic- which has a melting point below ordinary room temperature so there's some doubt about your meaning of your question "how does one think the metal would be embrittled in the short time the mix takes to solidify. ".
Who says it solidifies?
And, even if it does, gallium is noted for doing this trick, even when the mixture isn't molten (I said I'd come back to it).

Incidentally, don't start sentences with lower case letters.

Theoretic - 3-2-2016 at 19:19

I didn't mean to specifically use gallium as a glue component. Somehow it fits their system (and presumably doesn't embrittle the metal being joined) even though the Ga-containing phase is still liquid. But I didn't imagine using this specific mix without the nanorods; but rather any mix that does work. They didn't arrive at In/Ga for their system right away.

and yes thank you, Grammarian good sir. ßut I will start my sentences any way I bloody well please.

Theoretic - 27-2-2016 at 12:49

Indium is after all used as an adhesive to bond metals all on its own: https://en.wikipedia.org/wiki/Indium#Metal_and_alloys
Knowing its softness and everything-wetting character, this makes sense. Its ability to embrittle would be lower than gallium's, and it never becomes liquid during the bond formation.

1.6180339 - 27-2-2016 at 18:10

Now dysprosium is the most relatively useless substance. Methyl Cyanoacrylate (Super Glue) would be useful in the metallic mixture along with a chemical that reacts with another chemical (by shaking it) in the mixture to form water, which reacts with cyanoacrylate to polymerize.

unionised - 28-2-2016 at 02:28


Quote: Originally posted by Theoretic  
"... and galium on the other.
[Edited on 29-1-2016 by Theoretic]


Quote: Originally posted by Theoretic  
I didn't mean to specifically use gallium as a glue component.


Are you sure?

[Edited on 28-2-16 by unionised]

Theoretic - 16-3-2016 at 13:17

Quote: Originally posted by unionised  

Quote: Originally posted by Theoretic  
"... and galium on the other.
[Edited on 29-1-2016 by Theoretic]


Quote: Originally posted by Theoretic  
I didn't mean to specifically use gallium as a glue component.


Are you sure?

[Edited on 28-2-16 by unionised]


that first quote was from the article, and was describing their system, rather than what I was proposing.

[Edited on 16-3-2016 by Theoretic]

[Edited on 16-3-2016 by Theoretic]