aluminiumalloys

Aluminium alloys are materials in which aluminium is combined with other elements to improve properties such as strength, hardness, formability, or corrosion resistance. They are produced in wrought forms for shaping by rolling, extrusion, and bending, and in cast forms by pouring into molds. The major alloying elements include magnesium, silicon, manganese, copper, zinc, and lithium. The alloys are grouped into families by their principal alloying element: 2xxx (aluminium–copper), 3xxx (aluminium–manganese), 5xxx (aluminium–magnesium), 6xxx (aluminium–magnesium–silicon), and 7xxx (aluminium–zinc). These designations are followed by additional numbers that specify the exact alloy and temper in many standards.

2xxx and 7xxx alloys are among the strongest and are often heat-treatable; 6xxx alloys are popular for extrusions due to a balance of strength, workability, and corrosion resistance; 5xxx alloys are known for weldability and marine resistance; 3xxx alloys offer good formability with moderate strength. Processing methods include casting for complex shapes and wrought production for precise dimensions, with heat treatments such as solution treatment and aging to achieve desired properties. Common temper designations include T6 (solution heat-treated and artificially aged), T4 (solution heat-treated and naturally aged), and O (annealed).

Properties and limitations: aluminium alloys offer a high strength-to-weight ratio, good stiffness, and generally high corrosion resistance, though performance varies by alloy. They are highly recyclable, with substantial energy savings in recycling compared with primary production. Some high-strength grades, particularly certain 7xxx alloys, can be susceptible to stress-corrosion cracking and require careful joining and protective coatings.

Applications span aerospace, automotive, packaging (foil), construction, and consumer electronics, reflecting a broad balance of lightness, strength, and corrosion resistance.