I work in an archaeometallurgy lab and we recently received a few iron rings from a chainmail and after watching it under the microscope, I found out there's tin (actually, a Sn/Pb alloy, if anyone cares) between the overlapping ends of the ring. Someone suggested it was used as a mean of holding them together to rivet them easier, but I remember readig about tin being used as a coating in chainmails to prevent rusting, but I don't remember the source, and it might be my memory betraying me. Also, the rings are heavily corroded, so there's no way of telling if the rest of the ring was covered by tin as well.
So.... is this a possibility? Was tin ever used to coat chainmail rings?
(I don'y mind if it was in the roman age or during the renaissance or any other period).
Certainly a possibility!
This pair of sleeves from the Wallace Collection had once been tinned. That's actually the only maille that I know of having been tinned (galvanizing, but not tinning, is known to be used in India), but tinned plates and rivets weren't uncommon in that time period (15th-16th centuries)... I'm not sure about earlier periods.
Please publish findings, or as much as you can about where the maille is from, its age, etc. if you're able! It would be a great benefit to the community to have more evidence on something so rare.
Edit: got too excited and didn't read thoroughly, I now see that you specified the materials in the alloy.