Which Aluminum is best?

[vctech]

I am designing a pressure vessel for an submarine. I does anyone have any experience or suggestions with these alloys for this application?

Aluminum 5086 H111
Aluminum 5454 H111
Aluminum 5456 H111

Thanks

 

[EricFrance]

vctech,
What is the overall diameter of hull and the lenght?
Does the hull is protected by coating or not?
In fact, the aluminium alloy 5086 (or 5083), alone, is the better for marine corrosion resistant. Also, the 5754 may be used.
Other aluminium alloy my be used; for example, 6082 T6 (with anodic coating).
What is the fonctional pressure ?

 

[subsearobot]

The standard in the industry is 6061-T6 with a hard anodized coating. All aluminum alloys (some more than others, of course) will suffer from electrolitic corrosion due to necessary dissimilar metals in a sea water environment. for that reason, if you are not going to anodize, you must at least paint and use copius zinc anodes. If going this route, use the strongest alloy in your list.