I'm trying to make a Bismuth-Indium based low-melt alloy wetter (specifically, better at wetting to solid metals and glass). I've tried adding gallium, which obviously works, but due to its metal-attacking nature it can't be used here.

I know that antimony and tellurium are often used as surfactants, but I've only read of them acting as surfactants in organic solvents, and can't find anything on whether alloying them with a liquid metal would improve its wetting ability. As I don't have any Sb/Te at present, I'd rather ask if this has any chance of helping before trying them.

If not, is there anything else I could incorporate into the alloy - possibly a non-metal/metalloid - which would improve wetting?

  • $\begingroup$ I don't believe Sb and Te can act as surfactants in organic solvents. What you have read must have related to metal alloys. $\endgroup$ – Ivan Neretin Oct 24 '18 at 10:28

The surface of glass has many Si-O-H and Si-O-Si bonds; deeper inside would be Na and Ca and Al. An active metal might engage those surface atoms. Na might be too reactive (forming a dross of NaOH on the surface of your alloy, or reacting with water at the glass surface). Aluminum or zinc or perhaps magnesium might be active enough to contribute some sort of adhesion to glass.

Tin oxide is bound to glass surfaces for electrical conductivity. Perhaps it could be an intermediate layer, bonding glass and your alloy. And silver is deposited on glass to make mirrors. Your alloy might well stick to a silver deposit. So, while this doesn't actually make your alloy wetter, it could solve your problem of adhering to glass.

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    $\begingroup$ Titanium and chrome are great sticking layers onto glass. Of course, that just changes the wetting problem to a different interface... $\endgroup$ – Jon Custer Jan 14 '19 at 17:19

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