How does the addition of magnesium to aluminum alloys affect their properties?

Adding magnesium to aluminum alloys significantly enhances their strength, especially in the form of heat-treatable alloys known as Al-Mg or 5000 series alloys. Magnesium increases the alloy's resistance to corrosion, improves its formability, and raises its mechanical strength. These alloys are often used in applications requiring high strength-to-weight ratios, such as in the aerospace and automotive industries. The addition of magnesium also improves the alloy's weldability and resistance to stress corrosion cracking. However, it's important to note that excessive magnesium can lead to reduced ductility and increased susceptibility to stress corrosion cracking, so the amount added must be carefully controlled.