Corrosion resistance of Al Alloys
Corrosion resistance of Al Alloys
(OP)
Why do Al-Cu alloys in as-cast or heat treated conditions show weaker corrosion resistance in comparison with pure
Aluminum or Al-Si alloys?
Aluminum or Al-Si alloys?





RE: Corrosion resistance of Al Alloys
Among casting alloys, corrosion resistance is best for 5xx series (Al-Mg) followed by some of the 3xx series (those low in Cu, such as 356 and 360).
Although Si itself is very corrosion resistant due to forming a similarly protective amorphous SiO2 film, it can cause corrosion as Si is cathodic to Al. It also makes it difficult to increase the oxide thickness via the anodization process.
The effect of alloying on the corrosion resistance of aluminum alloys is more complex than this brief description. For further details, see
Corrosion of Aluminum and Aluminum Alloys, J.R. Davis, ed., ASM Int. (1999), http://www.asminternational.org/Template.cfm?Section=Br...
or various books on aluminum metallurgy and corrosion.
RE: Corrosion resistance of Al Alloys