The tops of carbonated beverage cans made with a different aluminum alloy than the pull tabs are with. Why?

The tops of carbonated beverage cans are made with a different aluminum alloy than the pull tabs because the two alloys have different corrosion rates. The tops of the cans are made with an alloy that is more resistant to corrosion, while the pull tabs are made with an alloy that is less resistant to corrosion. This is because the tops of the cans are exposed to the carbonated beverage, which can corrode the aluminum. The pull tabs, on the other hand, are not exposed to the carbonated beverage, so they do not need to be as resistant to corrosion.

Corrosion

Corrosion is the process of metal reacting with oxygen to form a metal oxide. This process is accelerated by the presence of water and salt, which are both found in carbonated beverages. The aluminum alloy that is used for the tops of cans is more resistant to corrosion than the aluminum alloy that is used for the pull tabs because it contains a higher percentage of magnesium and manganese. These elements help to form a protective oxide layer on the surface of the aluminum, which prevents the metal from corroding.

Conclusion

The tops of carbonated beverage cans are made with a different aluminum alloy than the pull tabs because the tops of the cans are exposed to the carbonated beverage, which can corrode the aluminum. The pull tabs, on the other hand, are not exposed to the carbonated beverage, so they do not need to be as resistant to corrosion.