To the welder about wrought aluminum alloys

  • Industrial wrought aluminum alloys are divided into seven series.
  • There are eight more - alloys, which do not fall in the first seven series and ninth – Reserve.
  • The difference between lots is different principal alloying elements.
  • The various alloying elements are given various properties of aluminum alloys.

unalloyed aluminum – 1xxx

  • 1xxx series alloys called "Alloy" is very conditional. This high purity versions of commercially pure aluminum. However, iron is often not only the impurity, but also alloying element - it increases the strength of aluminum.
  • The tensile strength of alloys of this series is from 70 to 150 MPa.
  • They are welded, although due to the narrow solidification interval require special welding technology.
  • Their high corrosion resistance makes them suitable for use in the chemical tanks and pipes.
  • Due to their high electrical conductivity is used for the manufacture of bus bars.
  • These aluminum alloys have relatively low strength properties and are therefore rarely used for structural elements.
  • They are often welded welding materials with the same chemical composition or welding aluminum alloys from 4xxx series, depending on the product destination and the conditions of its operation.

duralumin – 2xxx

  • This is a series thermally hardenable aluminum alloys.
  • The main alloying element is copper, from 0,7 to 6,8 %.
  • Their tensile strength of from 190 to 430 MPa. These high-strength alloys are frequently used in aerospace engineering and aircraft. They retain high strength in a wide temperature range.
  • Most of them are not considered to be welded by arc welding because of their tendency to hot cracking and stress corrosion.
  • However, in this series, there is a specially designed well-arc-welded aluminum alloys 2219 and 2519. They are often related welded high-strength alloy welding 2319. Sometimes, depending on the operating conditions of the weld, used for welding aluminum alloys from 4xxx series, containing silicon or silicon in combination with copper.

Aluminum-manganese alloys – 3xxx

  • Aluminum alloys of the series - not heat-hardened to a tensile strength of from 110 to 280 MPa.
  • The main alloying element - manganese, from 0,5 to 1,8 %.
  • They have moderate strength, good corrosion resistance, good formability and suitable for operation at elevated temperatures. they used to make kitchen utensils.
  • They are the main material in the manufacture of heat exchangers for vehicles, chemical plants and power stations.
  • Their modest strength properties make them unsuitable for structural applications.
  • Aluminum alloys 3xxx series weld welding alloys of the series 1xxx, 4xxx and 5xxx, Depending on their chemical composition, conditions of use and operation.

Welding aluminum alloys – 4xxx

  • This series consists of both thermally hardened, and thermally neuprochnyaemyh aluminum alloys.
  • Tensile strength – from 170 to 380 MPa.
  • Contains silicon from 0,6 to 21,5 %. Silicon lowers the melting point and increase the fluidity of the material during melting. These properties are quite favorable for them as materials for fusion welding and brazing.
  • Silicon, when it is itself, Aluminum makes thermally neuprochnyaemym, however, magnesium or copper additives make it a thermally hardenable alloy.
  • Usually these thermally hardenable alloys are used for welding only, when welded structure after welding must be subjected to heat treatment.

Aluminum-magnesium alloys – 5xxx

  • Thermally neuprochnyaemye aluminum alloys in this series have a tensile strength of 125 to 350 MPa.
  • Contains magnesium from 0,2 to 6,2 %.
  • These alloys have the highest strength among neuprochnyaemyh alloys and thermally well welded.
  • Widely used in the form of sheets and plates in shipbuilding, transport engineering, in the manufacture of pressure vessels, construction of bridges and buildings.
  • Aluminum alloys with magnesium content of up 2,5 % often successfully welded by welding aluminum alloys of the 5xxx series and 4xxx.
  • Alloy 5052 It is generally considered to limit the content of magnesium, when you can weld a welding alloy of the 4xxx series. This is due to reduced mechanical properties of welds occurring due eutectic submelting.
  • Therefore, alloys with high magnesium content is not welded welding alloys from 4xxx series, a series 5xxx alloys with similar chemical composition.

Cplavs aluminum-magnesium-silicon – 6xxx

  • These thermally hardenable aluminum alloys have a tensile strength of from 125 to 400 MPa.
  • Contains small amounts of magnesium and silicon - approx. 1 % each.
  • 6xxx series alloys are widely used in welded construction structures, mainly in the form of extruded sections.
  • These aluminum alloys are prone to hot-cracking during the solidification of the weld.
  • Therefore, they are not welded without filler wire or welding rod. Welding alloy is mixed in the weld pool with a weldable alloy and prevents hot cracking of the weld.
  • 6xxx alloys welded as a welding alloys 4xxx, and welding 5xxx alloys, depending on the purpose of the welded product and its conditions of use.

High-strength aluminum alloys – 7xxx

  • This series It includes thermally hardenable aluminum alloys with a strength of 220 to 610 MPa.
  • The main alloying element is zinc in an amount from 0,8 to 12,0 %.
  • The strongest aluminum alloys belong to this series.
  • 7xxx series alloys are used in aircraft, space technology, sports equipment.
  • As in the 2xxx series, most of the alloys of this series are not considered to be welded by arc welding.
  • However, it also has a well-weldable alloys, as, for example, alloy 7005, which is welded to the main welding alloys series 5xxx.


  1. Welding aluminium / T. Anderson –