Re: What commonly available alloy has the best corrorsion resistance properties?




"James" <jconaway@xxxxxxxxx> wrote in message
news:1138171378.334382.55740@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
> How does Aluminium stand up against stainless steel? Also would it help
> protect the metal if I coated it with gold?
>
I'd be inclined to think aluminum would tend to reduce to the ore from which
it came, assuming it got exposed to moisture. If not, it would likely
stand up to time just fine. It forms a skin of aluminum oxide almost
instantly when exposed to atmosphere, which protects it from further
corrosion.

A surface finish of gold would certainly make it more resistant to
corrosion, but you may not have the means to apply the gold. It's not as
easy as you might imagine, due to the aluminum reducing the gold from
solution, or the gold migrating into the aluminum after it has been applied,
assuming you were successful in getting it that far. A protective
barrier of nickel would probably have to be applied, then gold. It would
likely be cheaper in the long run to use stainless, which would be resistant
to corrosion from all atmospheric conditions, and would stand up better to
fire----although unless it was well insulated, the contents of the chamber
would be destroyed by heat. Aluminum, by contrast, would melt. In
either case, you're not going to be protected against excessive heat, so
you'll have to research proper insulation if that's a concern.

Harold


.



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