6063 aluminium alloy

AA 6063 is an aluminium alloy, with magnesium and silicon as the alloying elements. The standard controlling its composition is maintained by The Aluminum Association. It has generally good mechanical properties and is heat treatable and weldable. It is similar to the British aluminium alloy HE9.

6063 is mostly used in extruded shapes for architecture, particularly window frames, door frames, roofs, and sign frames. It is typically produced with very smooth surfaces fit for anodizing.

Basic properties

6063 has a density of 2.68g/cm^3 (0.0975 lb/cubic inch) ^[1]

Chemical composition

The alloy composition of 6063 is: ^[1]

• Silicon minimum 0.2%, maximum 0.6% by weight
• Iron no minimum, maximum 0.35%
• Copper no minimum, maximum 0.10%
• Manganese no minimum, maximum 0.10%
• Magnesium minimum 0.45%, maximum 0.9%
• Chromium no minimum, maximum 0.10%
• Zinc no minimum, maximum 0.10%
• Titanium no minimum, maximum 0.10%
• Other elements no more than 0.05% each, 0.15% total
• Remainder Aluminium

Mechanical properties

The mechanical properties of 6063 depend greatly on the temper, or heat treatment, of the material. ^[1]

6063-O

Un-heat-treated 6063 has maximum tensile strength no more than 19,000 psi (131 Mpa), and no specified maximum yield strength. The material has elongation (stretch before ultimate failure) of 18%.

6063-T1

T1 temper 6063 has an ultimate tensile strength of at least 17,000 psi (117 MPa) in thicknesses up to 0.5-inch (13 mm), and 16,000 psi (110 MPa) from 0.5 to 1.0-inch (25 mm) thick, and yield strength of at least 9,000 psi (62 MPa) in thickness up to 0.5-inch (13 mm) and 8,000 psi (55 MPa) from 0.5 to 1.0-inch (25 mm) thick. It has elongation of 12%.

6063-T4

T4 temper 6063 has an ultimate tensile strength of at least 19,000 psi (131 MPa) in thicknesses up to 0.5-inch (13 mm), and 18,000 psi (124 MPa) from 0.5 to 1.0-inch (25 mm) thick, and yield strength of at least 10,000 psi (69 MPa) up to 0.5-inch (13 mm) and 9,000 psi (62 MPa) from 0.5 to 1.0-inch (25 mm). It has elongation of 14%.

6063-T5

T5 temper 6063 has an ultimate tensile strength of at least 20,000 psi (152 MPa) in thicknesses up to 0.5-inch (13 mm), and 19,000 psi (145 MPa) from 0.5 to 1.0-inch (25 mm) thick, and yield strength of at least 14,000 psi (110 MPa) up to 0.5-inch (13 mm) and 13,000 psi (103 MPa) (from 0.5 to 1.0-inch (25 mm). It has elongation of 8%.

6063-T6

T6 temper 6063 has an ultimate tensile strength of at least 28,000 psi (196 MPa) and yield strength of at least 23,000 psi (165 MPa). In thicknesses of 0.124-inch (3.1 mm) or less, it has elongation of 8% or more; in thicker sections, it has elongation of 10%.

Other tempers

6063 is also produced in tempers T52, T53, T54, T55, and T832, with various improved properties.

Uses

6063 is used for architectural fabrication, window and door frames, pipe and tubing, and aluminium furniture.^[1]

Welding

6063 is highly weldable, using tungsten inert gas welding. Typically, after welding, the properties near the weld are those of 6063-0, a loss of strength of up to 30%. The material can be re-heat-treated to restore a higher temper for the whole piece.

See also

• Aluminium alloy

References

Further reading

• "Properties of Wrought Aluminum and Aluminum Alloys: 6063", Properties and Selection: Nonferrous Alloys and Special-Purpose Materials, Vol 2, ASM Handbook, ASM International, 1990, p. 103-104.