Aluminium alloy

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Aluminium alloys or aluminum alloys are alloys of aluminium, often with copper, zinc, manganese, silicon, or magnesium. They are much lighter and more corrosion resistant than plain carbon steel, but not quite as corrosion resistant as pure aluminium. Bare aluminium alloy surfaces will keep their apparent shine in a dry environment, but light amounts of corrosion products rub off easily onto skin when touched. Galvanic corrosion can be rapid when aluminium alloy is placed in proximity to stainless steel in a wet environment. Aluminium alloy and stainless steel parts should not be mixed in water-containing systems or outdoor installations.

Aluminum alloy compositions are registered with the Aluminum Association. Many organizations publish more specific standards for the manufacture of aluminium alloy, including the Society of Automotive Engineers standards organization, specifically its aerospace standards subgroups, ^[1] and the ASTM.

1 Alloy designations
2 Wrought aluminiums
3 Cast aluminiums
4 Named alloys
5 Common aluminum alloys
6 References

[edit] Alloy designations

Wrought and cast aluminium alloys use different identification systems. Wrought aluminium is identified with a four digit number where the first digit indicates the alloying elements, followed by a dash, a letter identifying the type of heat treatment and a 1 to 4 digit number identifying the specific temper. E.g. 6061-T6, the most common free-machining aluminium alloy. Cast aluminium alloys use a four to five digit number with a decimal point. The digit in the hundred's place indicates the alloying elements, while the digit after the decimal point indicates the form (cast shape or ingot)

[edit] Wrought aluminiums

1000 series are essenitally pure aluminium with a minimum 99% aluminium content by weight and can be work hardened
2000 series are alloyed with copper, can be precipitation hardened to strengths comparable to steel. Formerly referred to as duralumin, they were once the most common aerospace alloys, but were susceptible to stress corrosion cracking and are increasingly replaced by 7000 series in new designs.
3000 series are alloyed with manganese, and can be work hardened
4000 series are alloyed with silicon. They are also known as silumin
5000 series are alloyed with magnesium, derive most of their strength from solution hardening, and can also be work hardened to strengths comparable to steel
6000 series are alloyed with magnesium and silicon, are easy to machine, and can be precipitation hardened, but not to the high strengths that 2000, 5000 and 7000 can reach.
7000 series are alloyed with zinc, and can be precipitation hardened to the highest strengths of any aluminium alloy.
8000 series are a miscellaneous category

Wrought Aluminium Alloy Composition Limits (% weight)
Alloy	Si	Fe	Cu	Mn	Mg	Cr	Zn	V	Ti	Bi	Ga	Pb	Zr	Other		Al
Alloy	Si	Fe	Cu	Mn	Mg	Cr	Zn	V	Ti	Bi	Ga	Pb	Zr	each	total	Al
1060	0.25	0.35	0.05	0.03	0.03	0.03	0.05	0.05	0.03	0.03	0.03	0.03	0.03	0.03		99.6 min
1100	0.95 Si+Fe		0.05-0.20	0.05			0.10							0.05	0.15	99.0 min
2014	0.50-1.2	0.7	3.9-5.0	0.40-1.2	0.20-0.8	0.10	0.25		0.15					0.05	0.15	remainder
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	remainder
2219	0.20	0.30	5.8-6.8	0.20-0.40	0.02		0.10	0.05-0.15	0.02-0.10				0.10-0.25	0.05	0.15	remainder
3003	0.6	0.7	0.05-0.20	1.0-1.5			0.10							0.05	0.15	remainder
3004	0.30	0.7	0.25	1.0-1.5	0.8-1.3		0.25							0.05	0.15	remainder
3102	0.40	0.7	0.10	0.05-0.40			0.30		0.10					0.05	0.15	remainder
5052	0.25	0.40	0.10	0.10	2.2-2.8	0.15-0.35	0.10							0.05	0.15	remainder
5083	0.40	0.40	0.10	0.40-1.0	4.0-4.9	0.05-0.25	0.25		0.15					0.05	0.15	remainder
5086	0.40	0.50	0.10	0.20-0.7	3.5-4.5	0.05-0.25	0.25		0.15					0.05	0.15	remainder
5154	0.25	0.40	0.10	0.10	3.1-3.9	0.15-0.35	0.20		0.20					0.05	0.15	remainder
5454	0.25	0.40	0.10	0.50-1.0	2.4-3.0	0.05-0.20	0.25		0.20					0.05	0.15	remainder
5456	0.25	0.40	0.10	0.50-1.0	4.7-5.5	0.05-0.20	0.25		0.20					0.05	0.15	remainder
6005	0.6-0.9	0.35	0.10	0.10	0.40-0.6	0.10	0.10		0.10					0.05	0.15	remainder
6005A	0.50-0.9	0.35	0.30	0.50	0.40-0.7	0.30	0.20		0.10					0.05	0.15	remainder
6060	0.30-0.6	0.10-0.30	0.10	0.10	0.35-0.6	0.5	0.15		0.10					0.05	0.15	remainder
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	remainder
6063	0.20-0.6	0.35	0.10	0.10	0.45-0.9	0.10	0.10		0.10					0.05	0.15	remainder
6066	0.9-1.8	0.50	0.7-1.2	0.6-1.1	0.8-1.4	0.40	0.25		0.20					0.05	0.15	remainder
6070	1.0-1.7	0.50	0.15-0.40	0.40-1.0	0.50-1.2	0.10	0.25		0.15					0.05	0.15	remainder
6105	0.6-1.0	0.35	0.10	0.10	0.45-0.8	0.10	0.10		0.10					0.05	0.15	remainder
6162	0.40-0.8	0.50	0.20	0.10	0.7-1.1	0.10	0.25		0.10					0.05	0.15	remainder
6262	0.40-0.8	0.7	0.15-0.40	0.15	0.8-1.2	0.04-0.14	0.25		0.15	0.40-0.7		0.40-0.7		0.05	0.15	remainder
6351	0.7-1.3	0.50	0.10	0.40-0.8	0.40-0.8		0.20		0.20					0.05	0.15	remainder
6463	0.20-0.6	0.15	0.20	0.05	0.45-0.9		0.05							0.05	0.15	remainder
7005	0.35	0.40	0.10	0.20-0.7	1.0-1.8	0.06-0.20	4.0-5.0		0.01-0.06				0.08-0.20	0.05	0.15	remainder
7072	0.7 Si+Fe		0.10	0.10	0.10		0.8-1.3							0.05	0.15	remainder
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	remainder
7116	0.15	0.30	0.50-1.1	0.05	0.8-1.4		4.2-5.2	0.05	0.05		0.03			0.05	0.15	remainder
7129	0.15	0.30	0.50-0.9	0.10	1.3-2.0	0.10	4.2-5.2	0.05	0.05		0.03			0.05	0.15	remainder
7178	0.40	0.50	1.6-2.4	0.30	2.4-3.1	0.18-0.28	6.3-7.3		0.20					0.05	0.15	remainder

The "other" limits apply to all elements, whether a table column exists for them or not, for which no other limit is specified. alloy 6005A has another limit not shown above: the manganese plus chromium must be in the range of 0.12-0.50.

[edit] Cast aluminiums

x1xx.x series are minimum 99% aluminium
x2xx.x series copper
x3xx.x series silicon, copper and/or magnesium
x4xx.x series silicon
x5xx.x series magnesium
x7xx.x series zinc
x8xx.x series tin
x9xx.x series miscellaneous

[edit] Named alloys

Al-Li (aluminium, lithium)
Duralumin (copper, aluminium)
Nambe (aluminium plus seven other undisclosed metals)
Magnox (magnesium oxide, aluminium)
Zamak (zinc, aluminium, magnesium, copper)
Silumin (aluminium, silicon)
AA-8000: used for building wire per the National Electrical Code

[edit] Common aluminum alloys

These alloys are among the most commonly found alloys.

2011: Wire, rod, and bar for screw machine products. Applications where good machinability and good strength are required.
2014: Heavy-duty forgings, plate, and extrusions for aircraft fittings, wheels, and major structural components, space booster tankage and structure, truck frame and suspension components. Applications requiring high strength and hardness including service at elevated temperatures.
2024: Aircraft structures, rivets, hardware, truck wheels, screw machine products, and other miscellaneous structural applications. The first age-hardened alloy ever discovered.
2036: Sheet for auto body panels.
2048: Sheet and plate in structural components for aerospace application and military equipment.
2141: Plate in thicknesses of 40 to 150 mm (1.5 to 6.0 in.) for aircraft structures.
2218: Forgings; aircraft and diesel engine pistons; aircraft engine cylinder heads; jet engine impellers and compressor rings.
2219: Welded space booster oxidizer and fuel tanks, supersonic aircraft skin and structure components. Readily weldable and useful for applications over temperature range of -270 to 300 °C (-450 to 600 °F). Has high fracture toughness, and the T8 temper is highly resistant to stress-corrosion cracking.
2618: Die and hand forgings. Pistons and rotating aircraft engine parts for operation at elevated temperatures. Tire molds.

[edit] Common aerospace alloys

These are aluminium alloys which have a long history of being used in aircraft and other aerospace structures. ^[2]

[edit] Other aerospace alloys

These are currently produced, but less widely used, aluminium alloys for aerospace applications.

2090 aluminum
2124 aluminum
2195 aluminum - Al-Li alloy, used in Space Shuttle Super Lightweight external tank
2219 aluminum
2324 aluminum
6013 aluminum
7050 aluminum
7055 aluminum
7150 aluminum
7475 aluminum

[edit] Marine alloys

These alloys are used for boatbuilding and shipbuilding, and other marine and salt-water sensitive shore applications. ^[3]

5052 aluminum
5083 aluminum
5086 aluminum
6061 aluminum
6063 aluminum

[edit] References

^ SAE Aluminum specifications list, accessed Oct 8, 2006. Also SAE Aerospace Council, accessed Oct 8, 2006.
^ Fundamentals of Flight, Shevell, Richard S., 1989, Englewood Cliffs, Prentice Hall, ISBN 0-13-339060-8, Ch 18, pp 373-386.
^ Boatbuilding with Aluminum, Stephen F. Pollard, 1993, International Marine, ISBN 0-07-050426-1