Liquid Metal Thermal Paste

[skycrane]

when you tried to spread it out, did it compleatly eat through the aluminium foil???

[Fairydust]

when you tried to spread it out, did it compleatly eat through the aluminium foil???

Yes it did. I think it reacted with the aluminum to form a alloy which oxidises extremely fast. The oxide is very brittle and fell apart when I tried to spread the Gallium/ Indium alloy.

[alpha0ne]

Hmm very interesting, I look foward to seeing your results

When applied to aluminum does it give off any gases ??

[WeStSiDePLaYa]

i wonder if this stuff is toxic at all? and what about clean up and disposal of it? i use ceramique, since its cheap, works great, not conductive at all. so i dont need to worry about shorts if it somehow works its way onto pcb.

[Fairydust]

@alpha0ne:
I didn't see or smell any gas buildup at first, but since you asked i had to test for it. The simplest test i could devise, was to repeat the application under water. So i grabbed my scuba gear and headed down to to the north sea, finally there yours truly noticed he forgot to refill his cylinders, so back home I went.

Arriving home I came up with a simpler approach, simply use a glass beaker, attach aluminum foil to the bottom and fill it with water. When I applied a drop of the gallium/indium to the foil, it would not spread at all. I think the lack of oxygen preventened the gallium from building a layer of gallium oxide, which is the sticky stuff that enables the initial adhesion to the surface. Instead it kept it's mirror finish in drop form and would simply roll around the foil.

In phase two i tried applying the drop of gallium/indium in ambient air to a wet piece aluminum foil. The application took longer than in dry conditions, I noticed some water turning grey, which I think is the gallium oxide dissolving in the water and not sticking to the gallium and foil. After 1-2 minutes a grey layer formed on top of the aluminum , shortly after that bubbles appeared in the water layer. After about a minute of bubbling away, I was left with these
fluffy gray remains, 2

I am more a physics person than chemistry, so I will not try to explain it and screw up badly.

@ WeStSiDePLaYa: It is non toxic, both indium and gallium in metal form are non toxic, I am not 100% certain what additives are added, but they are all in metal form and very few metals are toxic, all of which would have no use in this alloy. Edit: It appears there are some studies suggesting indium has very low toxicity levels in Swiss mice. So it's safe to say we shouldn't use it as a food supplement in large qunatities. But for normal usage, I havn't seen any reports about toxicity