Why are aluminum-magnesium 5XXX alloys used for boats and beverage-can lids?

Aluminum-magnesium 5XXX alloys are utilized for boats and beverage-can lids primarily because they offer a superior combination of high strength, formability, corrosion resistance, and weldability.1

Specifically, these alloys are favored for the following reasons:

• Corrosion Resistance: The 5XXX series provides excellent resistance to corrosion, which is essential for marine environments in boat construction and for the storage of beverages in cans.1
• Mechanical Properties: These alloys are stronger than the 3XXX series while remaining highly formable, allowing them to be shaped into complex components like can lids or boat structures.1
• Fabrication: Their ability to be welded effectively makes them suitable for the assembly of welded structures, including boats and various sheet-metal works.1

While 3XXX alloys are commonly used for the bodies of beverage containers, the 5XXX series—such as alloy 5182—is specifically chosen for the lids to meet the necessary performance requirements for those components.1