Aluminum 6061, Al 6061-T6 Alloy Properties, Density, Tensile & Yield Strength, Thermal Conductivity, Modulus of Elasticity, Welding

6061 Aluminum Alloy (Al 6061-T6, 6061-T651, 6061-T4)

Al-6061 aluminum alloy is a general purpose structural alloy developed by Alcoa in 1935. The temper designations mainly have 6061-T4, T451, Al 6061-T6, 6061-T651, etc. It is one of the most widely used alloys. The main alloying elements are magnesium (Mg) and silicon (Si). The content of silicon and magnesium in this alloy is close to form magnesium silicide (Mg2Si), so it is a heat-treated wrought alloy.

Aluminum 6061-T6 has a minimum yield strength of 35 ksi (240 MPa), which is almost equal to that of A36 steel. This strength, combined with its light weight (about 1/3 that of steel), makes it particularly suitable for structural applications where static loads are a concern. Compared to 7000 (e.g. alloy 7075) and 2000 series (e.g. alloy 2024) aluminum, AA6061, although lower in strength, is less sensitive to solution heat treatment and quench variation.

Because 6061 aluminium alloy is easy to extrude, it can provide a variety of product forms such as sheet, strip, plate, rod, forgings, tubes, pipes, wires, extruded parts and structural shapes.

Aluminum 6061 has good corrosion resistance, mechanical properties, formability, weldability, and machinability. Generally suitable for medium to high strength requirements, and has good toughness. Applications range from food and beverage packaging, electronic products and home appliances, architectural decoration, transportation to aerospace components. Alloy 6082, popular in Europe, is slightly stronger than AA6061 and has similar uses.

The abbreviations Al-6061 and AA6061 in this article are the same material. Al-Aluminum; AA-the Aluminum Association or Aluminum Alloy.

Aluminum Alloy 6061 Properties, Data Sheet & Specs.

The following tables and lists summarize 6061 aluminum properties, datasheet and specs including chemical composition, physical properties and mechanical properties, welding, hardness, machinability, heat treating, etc.

Chemical Composition

Aluminium 6061 chemical composition is listed in the following table.

Notes (various standards of 6061 aluminum):

• ASTM B209: Aluminum and Aluminum-Alloy Sheet and Plate.
• ASTM B211: Rolled or Cold Finished Bar, Rod, and Wire.
• ASTM B221: Extruded Bars, Rods, Wire, Profiles and Tubes.
• ASTM B210: Aluminum and Aluminum-Alloy Drawn Seamless Tubes.
• ASTM B308/B308M: AL 6061-T6 Aluminum Structural Profiles.
• ASTM B241/B241M: Seamless Pipe and Seamless Extruded Tube.
• SAE AMS 4025: Sheet and Plate; Temper O; Annealed.
• SAE AMS 4026: Sheet and Plate; Temper T4, T42, T451 (-T4 Sheet, -T451), Solution Heat Treated and Naturally Aged.
• SAE AMS 4027: Sheet and Plate; Temper T6 Aluminum, T62, T651 (AL 6061-T6 Sheet, 6061T651 Plate) Solution and Precipitation Heat Treated.
• SAE AMS 4117: Rolled or Cold Finished Bars, Rods, and Wire and Flash Welded Rings; (AL 6061-T6 Aluminum, 6061-T651).

6061 Aluminum Physical Properties

6061 aluminum physical properties are given in the following lists, including density, melting point, coefficient of thermal expansion, elastic modulus, thermal conductivity, specific heat capacity electrical conductivity, and electrical resistance.

Notes:

• 10^-6·K^-1 = 10^-6/K = 1 μm/m·°C
• 1 Ω·mm²/m = 1 μΩ·m
• 1 g/cm3 = 1 kg/dm3 = 1000 kg/m3
• 1 GPa = 1 kN/mm2
• 1 MPa = 1 N/mm2

The melting range shown applies to wrought products with a thickness of 6.35 mm (1/4 in.) or greater.

Specific gravity: 2.7

Mechanical Properties

Aluminium 6061-T6 mechanical properties are listed in the following tables including yield strength (yield stress), ultimate tensile strength, shear strength, modulus of elasticity, young’s modulus, etc.

The following mechanical properties is the average value of various sizes, product forms and manufacturing methods, so the properties cannot be guaranteed. They are only used as a basis for comparing alloys and tempering, and should not be specified as engineering requirements or used for design purposes.

Notes for modulus of elasticity: The average of the tensile (Young’s modulus) and compressive modulus. The compression modulus is about 2% higher than the tensile modulus (Young’s modulus).

Mechanical Properties of Aluminum 6061-T6 in SAE AMS and ASTM Standard

Welding of 6061 Aluminum Alloy

Al-6061 alloy is easy to weld and connect by various methods. Usually welded with ER4043; For getting the best color matching, ER5356 is recommended.

The following table summarizes common similar metal welded joints made using inertial drive FRW.

Notes:

• Metal Loss: The total shortening of the workpiece during the welding process.
• Total Time: The sum of heating time plus welding time.

The following table gives parameters used for inertia welding several common dissimilar material combinations.

Note for Axial Force: A force of 22 KN (5000 lbf) is applied during the heating stage of the welding; the force near the end of the weld is subsequently increased to 67 KN (15000 LBF).

Notes:

• ① Postweld artificially aged only.
• ② For thicknesses greater than 19 mm (3/4 inch), 4643 filler is required.

Heat Treating of Aluminum 6061

AA-6061 Annealing

Typical full annealing treatment (O condition): The annealing process is an average process. Heat to 415 °C (775 °F) for 2 to 3 hours, then slowly cool (28 °C/hr) to 260 °C (500 °F). The intermediate annealing for removing cold work should be performed at 343 °C (650 °F). Time and cooling rate are not critical.

6061 Aluminium Aging

6061 aluminium alloy sheets, plates, rolled or cold-rolled wire, rods, bars, and drawn tubing are aged to a metal temperature of 160 °C (320 °F) and maintaining it for 18h. Extruded rods, rods, shapes and tubes; dies and hand forgings, rolled rings are aged to a metal temperature of 175 °C (345 °F) and held for 8 hours.

Al 6061 Alloy Corrosion Resistance

Al 6061 alloy has excellent corrosion resistance to atmospheric conditions and good corrosion resistance to seawater. This alloy also has a good finish and a good reaction to anodic oxidation. However, where appearance is crucial, consider using 6060 or 6063 alloy.

Typical Applications of 6061 Aluminum Alloy

Representative applications of 6061 aluminium alloy include aerospace and electrical fixtures, as well as communications. They are also widely used in automated machinery parts, precision machining, mold manufacturing, electronics and precision instruments, SMT, PC board solder carriers, etc.

• Aerospace: 6061 aluminium alloy can be used to make aircraft skins, fuselage frames, beams, rotors, propellers, fuel tanks, siding and landing gear pillars, as well as rocket forging rings, spacecraft siding, etc.
• Transportation: 6061 aluminium alloy also used for car, subway car, railway passenger car, high-speed passenger car body structural materials, doors and windows, shelves, automotive engine parts, air conditioners, radiators, body panels, wheels and ship materials.
• Packaging: Aluminum alloy 6061 is also used as metal packaging materials in the form of thin plates and foils, made into cans, lids, bottles, barrels, packaging foils, which are widely used in packaging of beverages, food, cosmetics, medicines, cigarettes, industrial products, etc.
• Printing: Mainly used to make PS plates. Aluminum-based PS plates are a new type of material for the printing industry. They are used for automatic plate making and printing.
• Architectural decoration: alloy 6061 is mainly used in building frames, doors and windows, suspended ceilings, metal curtains, perforated metal sheet, decorative surfaces, etc. Such as various architectural doors and windows, aluminum profiles for curtain walls, aluminum curtain wall panels, profiled panels, checkered panels, color coated aluminum panels, etc.
• Electronic home appliances: 6061 also used in various busbars, wiring, conductors, electrical components, refrigerators, air conditioners, cables and other fields.

6061 Aluminium Alloy Equivalent

Aluminum 6061 equivalent to European EN (German DIN EN, British BSI EN, France NF EN), ISO, Japanese JIS and Chinese GB standard (for reference).

Notes: DIN 1725-1 has been replaced by DIN EN 573-3.

Related materials: SAE 5160 Steel, Type 302 Stainless Steel, AISI 904L Stainless Steel, AISI 304 Stainless Steel, SAE 1080 Steel, X5CrNi18-10 (1.4301)