Identify this type of aluminum?

[ChazzC]

Anodizing converts the surface of aluminum oxide. The nature of the crystal growth is such that the surface has small tubes perpendicular to the surface and the coating is porous and can accept dye. When the anodizing,by heating in boiling water, the pores close over trapping the dye and sealing the surface. No additional coating is necessary. Then anodizing is compromised, it just falls away. It wouldn't peel as shown above.

Plating, on the other hand will peel. It is common to plate Zamak parts for protection against corrosion and to enhance appearance. When the plating is compromised, corrosion can occur underneath the plating, causing it to peel as shown. Zamak is tupically harder than a aluminum and metals like nickle are often used for plating which can further enhance surface hardness.

Thanks for the clarification

 

[markba633csi]

It looks like a high strength, light weight aluminum alloy like 2024
2024 tends to corrode like that after a long period in the elements