Aluminium alloy

Aluminum alloys caused by alloying aluminum with other metals, mainly manganese, magnesium, copper, silicon, nickel, zinc and beryllium. As a base material is used in most cases Al99, 5 ( EN AW- 1050A ). In this way, the strength values ​​can be increased within wide limits and also affect other properties.

Depending on whether the desired increase in strength is only achieved by alloying elements as well as work hardening or so primarily through a precipitation hardening (heat treatment), a distinction is made between the curable and non-age hardening (natural hard ) alloys.

A further distinction arises from the type of processing: wrought or cast materials. The wrought alloys are out of ultrapure and pure aluminum essentially the naturally hard alloys of the type AlMn, AIMg and AlMgMn and the heat-treatable alloys of the genera AlCuMg, AlCuSiMn, AIMgSi, AlZnMg and AlZnMgCu. They are processed into semi-finished in the form of strip, sheet and circles, tubes, rods and wires, extrusions and forgings. The cast materials include alloys of the genus AlSi, AlSiMg, AlSiCu, AIMg, AIMgSi, AlCuTi, AlCuTiMg.

Wrought aluminum alloys

As all aluminum Wrought aluminum alloys are referred to that are processed primarily by forming ( rolling, extrusion ) ( wrought ).

Even small additions of alloying elements magnesium, silicon, copper, zinc, nickel and manganese change the properties of pure aluminum very strong. In particular strength and hardness are increased, the reduced electrical conductivity, while the ductility decreases only slightly. These alloys exhibit high ductility, they are therefore called wrought aluminum alloys. Aluminum alloys are used because of their high strength and low density materials for transport containers as well as structural components in automotive, aircraft and shipbuilding.

Aluminum alloys are usually designated by their place with a material number created by the Aluminum Association four-digit numbering system. The first digit indicates the major alloying element and thus the alloy group. The remaining numbers are more or less count numbers are assigned in chronological order or in accordance with existing alloys.

  • 0.7 to 6.8 % Cu
  • Use in the aerospace industry
  • High strength
  • Wide temperature range.
  • Some alloys are not considered due to the risk of cracking during welding weldable as
  • Filler mostly 2xxx, 4xxx sometimes.
  • High corrosion resistance
  • Good formability
  • Suitable for higher temperatures
  • Application of cooking pots over cooler in vehicles ( here often with 4xxx plated ) to the power plant construction
  • Filler 1xxx, 4xxx and 5xxx.
  • 0.6 to 21.5 % Si
  • Contains only one series, the hardenable and non-hardenable alloys
  • For the curing, the presence of magnesium is additionally required. Silicon reduces the melting point and makes the melt more fluid
  • Ideal for welding and Brazing
  • 0.2 to 6.2 % Mg
  • Highest strength among the non -hardenable aluminum alloys
  • Weldable
  • Use in shipbuilding, transportation, pressure vessels, bridges and buildings, as AA5024 ( AlMgSc ) also for the aviation use. Filler must be determined according to magnesium content. Aluminum from this series with more than 3.0% Mg is not suitable for temperatures above 65 ° C ( stress corrosion cracking )
  • Materials with less than about 2.5 % Mg can often be successfully welded with 5xxx or 4xxx welding consumables. 5032 is usually cited as the material with the highest Mg content, which is just welded with 4xxx.
  • Si and Mg at 1%
  • Very popular with Weldments
  • Intended primarily for use as extruded profiles
  • May well be heat treated
  • Should not be welded without filler ( hot tears )
  • Welding consumables 4xxx and 5xxx.
  • 0.8 to 12.0 % Zn
  • Use in aircraft, aerospace, sports equipment
  • Some alloys are not weldable with arc
  • Alloys 7005 (trade name Ergal ) and 7020 are readily welded with 5xxx filler metals, as these two alloys contain copper

List of typical aluminum alloys, which are used in industry:

  • Aludur ( 0.3-1 % silicon, 0.3-0.8 % manganese and 0.5-1.2 % magnesium)
  • Aluman (1.1% manganese)
  • Duralumin ( 2.5-5.5 % copper, 0.2 ... 5 % magnesium, 0.5-1.2 % 0.2-1.0 % manganese and silicon )
  • Hydronalium (3-12 % magnesium, 0.2-0.8 % 0.2-1.0 % manganese and silicon )
  • Silumin (up to 14 % silicon )

Aluminum casting alloys

For cast alloys, the following classification shall apply:

The most important is the type of die-cast eutectic alloy of aluminum and silicon. Their eutectic is about 12 % of silicon and has a melting point of 576 ° C. This aluminum -silicon alloy has excellent castability ( fluidity, low shrinkage ), and has high strength. They can be welded well in general and is corrosion resistant. However, increasing proportions of magnesium and copper, the strength, the corrosion resistance of copper is reduced.

Cast aluminum alloys containing these elements are used as materials for example for motor housing and gear housing in vehicle and aircraft.

Aluminium Structural robustness Aluminium-lithium alloy
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