| 99.99 |
Pure Al in sheet, plate or extrusion |
Gives highest reflectivity since oxidized
surface is free of Si, Fe and Mn which normally obscure
polished surface. Easily formable, but low in strength, and
expensive. Used primarily for simulated gold finish.
Super-purity Al-Mg and Al-Mg-Si alloys give the same
brightness; cost is still high, but strength is much improved
because of Mg additions. |
5005
5252
5257
5357
5457
5557
5657 |
Al-Mg alloy in sheet form |
Reflectivity is below that of high-purity Al-Mg
alloys, but they respond well to anodizing, have good
mechanical properties, and are priced for commercial
applications like automotive, appliance, and architectural
trim. Alloying constituents do not tint coatings. |
| 6063 |
Extrusion Alloys |
These heat-treatable alloys combine high
strength and good response to anodizing. Contain Mg and Si as
MgSi. Heat treatment dissolves silicide, improving strength
and luster after anodizing. Presence of Si can give coating a
gray or brown tint. Alloy 5005 has some Mg for moderate
strengthening. |
| 1100 |
Sheet and plate |
Alloy 1100 is commercially pure Al, but has some
Si and Fe which diminish reflectivity under anodized coating.
Presence of Si can give coating a gray or brown tint. Alloy
5005 has some for moderate strengthening. |
| 3003 |
Al-Mn alloy in sheet or plate |
This commercial alloy has excellent formability
and, though widely used for anodic finishing, has less
reflectivity than 1100 or 5005 after anodizing because of Mn
and lower Al purity. Since MnO is brown, thick anodized films
on this alloy have a brownish tint. |
| 5052 |
Al-Mg alloy in sheet or plate |
Structural alloy containing Cr as well as Mg,
widely used for welded parts. Presence of Cr gives thicker
anodic coatings a yellowish tint. |
6061
2014
2024
7075 |
Extrusion, sheet and plate |
Heat-treatable, these alloys rank after 5052 in
reflectivity because Al purity is lower. Cr in 6061 and 7075
gives thicker anodic coatings a yellowish tint. |
| Reprinted from Product Engineering |
