The 5xxx series of aluminum alloys contain magnesium, making them some of the strongest non-heat-treatable alloys available. These alloys are also exceptionally tough and can absorb a lot of energy before fracturing, making them suitable for critical applications that require superior toughness. They are easily weldable using standard commercial methods.
Additionally, 5xxx alloys have excellent resistance to atmospheric and seawater corrosion, making them suitable for use in harsh marine environments, as explained in more detail in Chapter 6. However, it’s worth noting that alloys with more than 3% magnesium are not recommended for applications with significant exposure to high temperatures because they may become sensitized to stress-corrosion cracking (SCC). For such applications, alloys like 5052, 5454, and 5754, which contain less magnesium, are recommended instead.