SELECTION AND APPLICATIONS
OF WROUGHT ALUMINUM AND
ALUMINUM ALLOYS
Arif Uddin Prio – 1511001
S.M Farhaduzzaman - 1511015
Wreet Sarker - 1511016
Wrought Aluminum Alloys
Wrought
aluminum
alloys can be
broadly
classified into
two basic
types:
•Non Heat-treatable alloys
•Heat-treatable alloys
Non Heat-treatable alloys
◦ Various grades of pure aluminum
◦ Alloys that derive their strength from:
Solid solution strengthening
Cold-work or strain hardening
Heat-treatable alloys
◦ Alloys that contain one or more of the
elements of copper, magnesium,
silicon and zinc.
◦ Have the characteristics of increasing
solubility in aluminum with increasing
temperature.
◦ Examples: 1xxx, 3xxx, 4xxx, 5xxx and few
belonging to 7xxx and 8xxx series.
◦ Generic characteristics for
precipitation hardening.
◦ Examples: 2xxx, 6xxx, 7xxx and few of
4xxx and 5xxx series.
Non Heat-treatable alloys
◦ Various grades of pure aluminum
◦ Alloys that derive their strength from:
Solid solution strengthening
Cold-work or strain hardening
Heat-treatable alloys
◦ Alloys that contain one or more of the
elements of copper, magnesium,
silicon and zinc.
◦ Have the characteristics of increasing
solubility in aluminum with increasing
temperature.
◦ Examples: 1xxx, 3xxx, 4xxx, 5xxx and few
belonging to 7xxx and 8xxx series.
◦ Generic characteristics for
precipitation hardening.
◦ Examples: 2xxx, 6xxx, 7xxx and few of
4xxx and 5xxx series.
Non Heat-treatable alloys
Non Heat-treatable alloys exhibit very low yield and
tensile strength in the annealed state and therefore are
easily formable(workable) to different shapes.
1xxx Alloys
◦ 99.00% or more pure aluminum
◦ Large application in electrical and chemical industry
◦ Properties:
Excellent corrosion resistance
High thermal and electrical conductivities
Low mechanical properties
Excellent workability
Applications
◦ Typical uses: chemical equipment, reflectors, heat exchangers, electrical
conductors and capacitors and so on.
◦ One of the important applications of pure aluminum is as a cladding material
to:
Improve the corrosion resistance of heat-treatable alloys
Improve the finishing characteristics of non heat-treatable alloys
3xxx Alloys
◦ Manganese is the major alloying element of this group.
◦ Have about 20% more strength than 1xxx alloys due to dispersion and solid
solution hardening.
◦ Manganese content is limited to 1.5% in these alloys.
◦ Few alloys contain magnesium as an extra alloying element.
Applications
◦ Alloys 3003, 3004 and 3105 are used as general purpose alloys for moderate
strength application which require good workability.
◦ Other applications include beverage cans, cooking utensils, storage tanks,
highway signs etc.
◦ They constitute most used aluminum alloys, tonnage wise.
4xxx Alloys
◦ Silicon is the major alloying element in these group.
◦ Silicon can be added in a substantial amount (up to 12%) to cause a dramatic
lowering of melting range without producing brittleness. Hence, are not
characterized by their mechanical properties.
◦ Normally non heat-treatable but when used to heat the heat treatable alloys
will pick some constituents of heat treatable alloys and will respond to heat
treatment to a limited extent.
Applications
◦ Major use of aluminum-silicon alloys is as welding wires and brazing alloys in the
joining of aluminum alloys.
◦ Alloys which have high amount of silicon become dark gray to charcoal when
surface anodized and thus have great demand in architectural applications.
◦ Alloy 4032 is used to produce forged engine pistons.
5xxx Alloys
◦ Magnesium is the major alloying element along with some manganese.
◦ Produces moderate to high strength alloys that can be cold worked or strain
hardened.
◦ Magnesium is highly effective as a hardener.
◦ Were developed as marine alloys due to high resistance in salty marine
environment and good weldability.
◦ Certain restrictions are placed on the amount of cold work and the operating
temperature to avoid susceptibility to stress corrosion cracking.
Applications
◦ Uses include architectural, ornamental, decorative trim, can and can ends.
◦ Also used in boats and ships, cryogenic tanks, crane parts and automotive
structures.
8xxx Alloys
◦ These alloys encompass variety of compositions, including non heat-treatable
and heat-treatable.
◦ Among non heat-treatable 8001 (aluminum-nickel-iron alloy) has good
corrosion resistance in water at high temperature and pressure and shows
similar properties to that of 3003.
◦ 8081 containing 20% Sn and 1% Cu has bearing characteristics superior to
other alloys for automotive use.
Applications
◦ 8001 is used in nuclear energy applications.
◦ 8280(aluminum-tin-nickel-copper alloy) is used in bearings. Tin provides
antifriction characteristics, while nickel and copper contribute to
strengthening.
◦ 8090 is a heat-treatable aluminum-lithium alloy that is being develop to used in
aerospace industry.
Others
◦ Aluminum alloy foil is a widely used wrought product. Generally produced
commercially from non heat-treatable alloys.
◦ Aluminum honeycomb core for aircraft is made of 3003-19, 5052-H39.
Heat-Treatable Alloys
These alloys are basically selected for structural applications because of
their high strengths and for the inherent lightness and corrosion resistance
of aluminum.
2xxx Alloys
• Copper is the principle alloying element in these alloys.
• These alloys don’t have a good corrosion resistance like most other aluminum
alloys.
• Under certain conditions, these alloys may be prone to intergranular corrosion.
• So, to provide galvanic protection, these alloys are often claded with high
purity aluminum or magnesium- silicon alloy in the form of sheets.
Applications
• These alloys find widespread use for parts and structures requiring high specific
strengths.
• Commonly used in truck and aircraft wheels, truck suspension parts, aircraft
fuselage, wing skins, and other structural parts requiring good strength at
temperature below 150°C.
• Except for alloy 2219, these alloy have limited weldability.
6xxx Alloys
• These alloys contain silicon & magnesium in the proportion to form Mg2Si.
• Mg2Si precipitates out & strengthens the alloy during heat treating.
• They have medium strength, good formability, weldability, machinability & corrosion
resistance.
Uses include architectural applications, bicycle frames, transportation equipment, bridge
railings and welded structures.
7xxx Alloys
• These alloys contain zinc, from 1 to 8 percent, and a small amount of magnesium to
produce moderate to very high strength alloys.
• High strength 7xxx alloys exhibit reduced SCC resistance.
• Used in slightly over aged condition to provide better combinations of strength,
corrosion resistance, and fracture toughness.
• They are used in airframe structures, mobile equipment, and highly stressed parts.
Tensile Properties
Aircraft Alloys
• Because of their high specific strengths and specific moduli, the alloys 2024
and 7075 have been the conventional aircraft structural materials.
• They constitute 70-80 percent of the weight of the aircraft.
• Higher toughness
requirements have been
met through the high
purity modification of
these alloys such as
2124,2224,7175,7475, and
with alloy 7075.
• In addition, 2219 is used for
good weldability and high
temperature strength,
modified as 2419 for higher
toughness.
Aluminum-Lithium alloys
• They are also heat treatable alloys but have yet to be fully commercialized.
• They are targeted to replace the conventional aluminum alloys 2024 and 7075
in the aircraft.
• These alloys are very lighter and yet have higher moduli than the
conventional aluminum alloys.
• They also exhibit better toughness and fatigue properties.
Alclad & Clad Aluminum Products
• Aluminum products are sometimes coated on one or both surfaces with a
metallurgical bonded, thin layer of pure aluminum or aluminum alloy.
• If the combination of core and alloys is selected so that the cladding is anodic
to the core, the product is called alclad.
• A clad product, on the other hand, is a combination in which the cladding is
not intentionally made anodic to the core.
• Cladding of the Alclad products protects the core at exposed edges as well
as abraded or corroded areas and acts as a sacrificial anode.
• Clad products are designed to provide improved surface appearance.
• Brazing products are commercial example of clad products in which cladding
alloy has a lower melting point than the core. This helps the subsequent joining
of several parts into an assembly.
• The corrosion potentials of cladding and core must be sufficiently different, with the
cladding being anodic, in order to protect the core.
• Pure aluminum, 1060, is about
0.15V more anodic than 2024-T3
and -T4 tempers.
• So, 1060 is used for most Alclad
2xxx products.