Analysis of 6000 Series Aluminum Alloys

Generally speaking, Aluminum alloys can be grouped upon the particular material’s characteristics, such as the primary elemental component as well as its ability to respond to thermal and mechanical treatment. Aluminum Alloys are composed of one or more elements of which one is Aluminum. Most aluminum alloys contain 90 – 96% aluminum, with one or more other elements added to provide a specific combination of properties and characteristics.

When considering the classification system used for aluminum alloys, the above characteristics are of special interest. The wrought and cast aluminums have different systems of identification; the wrought having a 4-digit system, and the castings having a 3-digit and 1-decimal place system.

As Orange Aluminum primarily uses wrought Aluminum 6061 and 6063 alloys we will focus primarily on their properties.

These 6000 Series alloys are aluminum - magnesium - silicon alloys (magnesium and silicon additions of around 1.0%, in the form of magnesium silicon – Mg₂Si) and are found widely throughout the fabrication industry, used predominantly in the form of extrusions, and incorporated in many structural components. The addition of magnesium and silicon to aluminum produces a compound of magnesium-silicon (Mg₂Si), which provides this material its ability to become solution heat treated for improved strength. In addition to Mg₂Si , 6061 alloys typically contain 0.28% Cu, 0.20% Cr; 6063 alloys contain 0.7% Mg.

6063 alloy is one of the most popular alloys in the 6000 series, as the alloying components allow for great extruded ability and a high quality surface finish. This alloy is used in several industries, including:

•Door and Window Frames

•Railings and Furniture

•Architectural and Building Products

•Electrical Components and Conduit

•Pipe and Tube for Irrigation Systems

After being heat-treated, this alloy is corrosion-resistant as well as resistant to stress corrosion. 

This alloy is also often used in electrical applications in the T5, T52 and T6 tempers due to its good electrical conductivity. In T1, T4, and T52 tempers is provides for good formability. For anodizing purposes, T5 and T52 tempers provide a great surface for a classic matte finish.

6061 alloy is one of the most widely used alloys in the 6000 series. It is one of the most versatile of the heat-treatable allows; it is very popular for medium to high strength uses and has great toughness characteristics. This alloy is used in several industries, including:

• Aircraft and automotive components
• Machinery and Equipment Applications
• Recreation Products
• Consumer Goods, such as soda cans and aluminum foil

6061 is used by many extrusion houses for rod and bar products, including pipes and tubes. This alloy has excellent corrosion resistance to atmospheric conditions and good corrosion resistance to sea water.

This alloy also offers good finishing characteristics and responds well to anodizing; however, if cosmetic appearance is critical, 6063 is preferred.

Temper

Temper refers to the degree of hardness and elasticity in metals. The physical properties exhibited by aluminum alloys are significantly influenced by the treatment of the material. In addition to heat treating, factors that contribute to the Temper include aging temperature, annealing temperature, and solution temperature.

The temper designation appears as a hyphenated suffix to the basic alloy number, such as 6063-T5.

Products which are thermally treated with or without supplementary strain-hardening are designated with a T temper code allocated and registered by The Aluminum Association.

• T1 - Cooled from an elevated temperature shaping process and naturally aged to a substantially stable condition.
• T2 - Cooled from an elevated temperature shaping process, cold worked, and naturally aged to a substantially stable condition.
• T3 - Solution heat treated, cold worked, and naturally aged to a substantially stable condition.
• T4 - Solution heat treated, and naturally aged to a substantially stable condition.
• T5 - Cooled from an elevated temperature shaping process then artificially aged.
• T6 - Solution heat treated then artificially aged.
• T7 - Solution heat treated then overaged/stabilized.
• T8 - Solution heat treated, cold worked, and then artificially aged.
• T9 - Solution heat treated, artificially aged, then cold worked.
• T10 - Cooled from an elevated temperature shaping process, cold worked, then artificially aged.