About Aluminium alloys

1. Aerospace Aluminum Alloys
6061, 7075, 2024 Chemical Composition
Chemical Composition Limitsfor Aluminum Alloys
Composition in percent by weight according to The Aluminum Association. The values associates maximum limits unless shown as a range or a minumum.
Alloy Si Fe Cu Mn Mg Cr Zn Ti
Others
Each
Others
Total
Al.
Min.
6061
0.40-
0.8
0.7
0.15-
0.40
0.15
0.8-
1.2
0.04-
0.35
0.25 0.15 0.05 0.15 Rem.
7075 0.40 0.50 1.2-2.0 0.30
2.1-
2.9
0.18-
0.28
5.1-
6.1
0.20 0.05 0.15 Rem.
2024 0.50 0.50 3.8-4.9
0.30-
0.9
1.2-
1.8
0.10 0.25 0.15 0.05 0.15 Rem.
6061, 7075, 2024 Mechanical Properties
Typical Mechanical Properties
The following typical properties are not guaranteed since most cases they are averages for various sizes and methods of manuf acture and may not be exactly representative of any particular
product or size. The data is intended for comparing alloys and tempers and should not be used for design purposes.
Tensile
Strength
Yield
Strength
Elongation (%) for the
following gauge
ranges:
Tensile
Strength
Yield
Strength
Elongation (%) for
the following gauge
ranges:
Alloy Temper (ksi) (ksi)
0.010-
0.050
0.051-.125 (MPa) (MPa)
0.25-
1.25mm
1.26-
3.0mm
6061
O 18 8 25 26 124.1 55.2 25 26
T4 35 21 22 24 241.3 144.8 22 24
T6 45 40 12 17 310.3 275.8 12 17
2024
O 27 11 18 20 186.2 75.8 18 20
T3 70 50 16 18 482.6 344.7 16 18
T4 68 47 20 19 468.8 324.1 20 19
Aluminum Specification Cross Reference
Alloy Form ASTM AMS ASME
6061
Aluminum Coil ASTM-B209
4025, 4026, 4027AMS-
QQ-A-250/11
SB-209
Aluminum Strip ASTM-B209
4025, 4026, 4027AMS-
QQ-A-250/11
SB-209
Aluminum Plate ASTM-B209
4025, 4026, 4027AMS-
QQ-A-250/11
SB-209
2024
Aluminum Coil ASTM-B209 4035, 4037
Aluminum Strip ASTM-B209 4035, 4037
Aluminum Plate ASTM-B209
4035, 4037
Othergeneral differences
Characteristics 2024 6061
Weldability Poor Good
Machining Average Good
Corrosion
Resistance
Poor Very Good
2024-T3 Aluminum
Minimum
Properties
Ultimate Tensile
Strength, psi
70,000
Yield Strength, psi 50,000
Brinell Hardness 120
Rockwell Hardness B75
Chemistry Aluminum (Al) 90.7 -
94.7%
Chromium (Cr) 0.1% max
6061-T6 Aluminum
Phy sical and Mechanical
Properties
Ultimate Tensile
Strength, psi
45,000
Yield Strength, psi 40,000
Brinell Hardness 95
Rockwell Hardness B60
Chemistry Aluminum (Al) 95.8 - 98.6%
Chromium (Cr) 0.04 - 0.35%
Copper (Cu) 0.15 - 0.40%

2. Copper (Cu) 3.8 - 4.9%
Iron (Fe) 0.5% max
Magnesium (Mg) 1.2 - 1.8%
Manganese (Mn) 0.3 - 0.9%
Silicon (Si) 0.5% max
Iron (Fe) 0.70%
Magnesium (Mg) 0.8 - 1.2%
Manganese (Mn) 0.15% max
Silicon (Si) 0.4 - 0.8%
Zinc (Zn) Zinc (Zn) 0.25%
6061
This is the least expensive and most versatile of the heat-treatable aluminum alloys. It has most of the good qualities of aluminum. It offers a range of good mechanical
properties and good corrosion resistance. It can be fabricated by most of the commonly used techniques. In the annealed condition it has good workability. In the T4 condition
fairly severe forming operations may be accomplished. The full T6 properties may be obtained by artificial aging. It is welded by all methods and can be furnace brazed. It is
available in the clad form (“Alclad”) with a thin surface layer of high purity aluminum to improve both appearance and corrosion resistance. Applications: This grade is used for a
wide variety of products and applications from truck bodies and frames to screw machine parts and structural components. 6061 is used where appearance and better corrosion
resistance with good strength are required.
2024
This is one of the best known of the high strength aluminum alloys. With its high strength and excellent fatigue resistance, it is used to advantage on structures and parts where
good strength-to-weight ratio is desired. It is readily machined to a high finish. It is readily formed in the annealed condition and may be subsequently heat treated. Arc or gas
welding is generally not recommended, although this alloy may be spot, seam or flash welded. Since corrosion resistance is re latively low, 2024 is commonly used with an
anodized finish or in clad form (“Alclad”) with a thin surface layer of high purity aluminum. Applications: aircraft structural components, aircraft fittings, hardware, truck wheels
and parts for the transportation industry.