2218

aluminium alloy An aluminium alloy (or aluminum alloy; see spelling differences) is an alloy in which aluminium (Al) is the predominant metal. The typical alloying elements are copper, magnesium, manganese, silicon, tin, nickel and zinc. There are two principal ...

is an alloy in the wrought aluminium-copper family (2000 or 2xxx series). It is one of the most complex grades in the 2000 series, with at least 88.4%

aluminium Aluminium (aluminum in American and Canadian English) is a chemical element with the symbol Al and atomic number 13. Aluminium has a density lower than those of other common metals, at approximately one third that of steel. I ...

by weight. Unlike most other aluminium-copper alloys, 2218 is a high work-ability alloy, with relatively low for 2xxx series alloy yield strength of 255 MPa. Despite being highly alloyed, it have a good corrosion and oxidation resistance due sacrificial anode formed by magnesium inclusions, similar to marine-grade 5xxx series alloys. Although 2218 is wrought alloy, owing to granular structure it can be used in

casting Casting is a manufacturing process in which a liquid material is usually poured into a mold, which contains a hollow cavity of the desired shape, and then allowed to solidify. The solidified part is also known as a ''casting'', which is ejected ...

and been precisely machined after casting. It is easy to weld, coat, or glue. Good workability, thermal conductivity and dimensional stability make 2218 alloy a material of choice whenever high-precision parts subject to thermal shocks (especially piston engine cylinders and cylinder heads) are needed. 2218 alloy can be heat treated to increase tensile strength in expense of workability, with most common grades been F, T61, T71 and T72. Alternative names for 2218 alloy are A2218 and A92218.

Chemical Composition

The chemical composition of 2218 alloy is poorly standardized, with several variants in production. All variants include both copper (4%) and magnesium (1.5%) as major alloying elements. Common alloy variants also include 2% of nickel. The alloy composition of 2218 aluminium is:2218-T72 Aluminium
/ref> *

Aluminium Aluminium (aluminum in American and Canadian English) is a chemical element with the symbol Al and atomic number 13. Aluminium has a density lower than those of other common metals, at approximately one third that of steel. I ...

: 91.35 to 92.95% *

Copper Copper is a chemical element with the symbol Cu (from la, cuprum) and atomic number 29. It is a soft, malleable, and ductile metal with very high thermal and electrical conductivity. A freshly exposed surface of pure copper has a pinkis ...

: 3.5 to 4.5% *

Magnesium Magnesium is a chemical element with the symbol Mg and atomic number 12. It is a shiny gray metal having a low density, low melting point and high chemical reactivity. Like the other alkaline earth metals (group 2 of the periodic ta ...

: 1.2 to 1.8% *

Nickel Nickel is a chemical element with symbol Ni and atomic number 28. It is a silvery-white lustrous metal with a slight golden tinge. Nickel is a hard and ductile transition metal. Pure nickel is chemically reactive but large pieces are slow to ...

: 1.7 to 2.3% *

Iron Iron () is a chemical element with symbol Fe (from la, ferrum) and atomic number 26. It is a metal that belongs to the first transition series and group 8 of the periodic table. It is, by mass, the most common element on Earth, right in f ...

: 1% max *

Silicon Silicon is a chemical element with the symbol Si and atomic number 14. It is a hard, brittle crystalline solid with a blue-grey metallic luster, and is a tetravalent metalloid and semiconductor. It is a member of group 14 in the periodic tab ...

: 0.9% max *

Zinc Zinc is a chemical element with the symbol Zn and atomic number 30. Zinc is a slightly brittle metal at room temperature and has a shiny-greyish appearance when oxidation is removed. It is the first element in group 12 (IIB) of the periodi ...

: 0.25% max *

Manganese Manganese is a chemical element with the symbol Mn and atomic number 25. It is a hard, brittle, silvery metal, often found in minerals in combination with iron. Manganese is a transition metal with a multifaceted array of industrial alloy use ...

: 0.5% max *

Tin Tin is a chemical element with the symbol Sn (from la, stannum) and atomic number 50. Tin is a silvery-coloured metal. Tin is soft enough to be cut with little force and a bar of tin can be bent by hand with little effort. When bent, t ...

: 0.25% max *

Chromium Chromium is a chemical element with the symbol Cr and atomic number 24. It is the first element in group 6. It is a steely-grey, lustrous, hard, and brittle transition metal. Chromium metal is valued for its high corrosion resistance and hardne ...

: 0.1% max

References

Aluminium alloy table

{{Aluminium alloys Aluminium alloys Aluminium–copper alloys

Chemical Composition

See also

References

Aluminium alloy table