5086 is an

aluminium–magnesium 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 ...

, primarily alloyed with

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 ...

. It is not strengthened by heat treatment, instead becoming stronger due to

strain hardening In materials science, work hardening, also known as strain hardening, is the strengthening of a metal or polymer by plastic deformation. Work hardening may be desirable, undesirable, or inconsequential, depending on the context. This strengt ...

, or cold mechanical working of the material. Since heat treatment doesn't strongly affect the strength, 5086 can be readily welded and retain most of its mechanical strength. The good results with welding and good corrosion properties in seawater make 5086 extremely popular for vessel gangways, building boat and yacht hulls.Boatbuilding with Aluminum, Stephen F. Pollard, 1993,

Basic properties

5086 has a density of , with a specific gravity of 2.66. Melting point is .

Chemical properties

The alloy composition of 5086 is:5086 Material properties
at supplliersonline.com, accessed October 29, 2006 *

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 ...

- 0.05%–0.25% by weight *

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 ...

- 0.1% maximum *

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 ...

- 0.5% maximum *

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 ...

- 3.5%–4.5% *

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 ...

- 0.2%–0.7% *

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 ...

- 0.4% maximum *

Titanium Titanium is a chemical element with the symbol Ti and atomic number 22. Found in nature only as an oxide, it can be reduced to produce a lustrous transition metal with a silver color, low density, and high strength, resistant to corrosion in ...

- 0.15% maximum *

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% maximum * Others each 0.05% maximum * Others total 0.15% maximum * Remainder

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 ...

Mechanical properties

The mechanical properties of 5086 vary significantly with hardening and temperature.

–O hardening

Unhardened 5086 has a

yield strength In materials science and engineering, the yield point is the point on a stress-strain curve that indicates the limit of elastic behavior and the beginning of plastic behavior. Below the yield point, a material will deform elastically and wi ...

of and

ultimate tensile strength Ultimate tensile strength (UTS), often shortened to tensile strength (TS), ultimate strength, or F_\text within equations, is the maximum stress that a material can withstand while being stretched or pulled before breaking. In brittle materials t ...

of from . At

cryogenic In physics, cryogenics is the production and behaviour of materials at very low temperatures. The 13th IIR International Congress of Refrigeration (held in Washington DC in 1971) endorsed a universal definition of “cryogenics” and “cr ...

temperatures it is slightly stronger: at , yield of and ultimate tensile strength of ; above its strength is reduced. Elongation, the

strain Strain may refer to: Science and technology * Strain (biology), variants of plants, viruses or bacteria; or an inbred animal used for experimental purposes * Strain (chemistry), a chemical stress of a molecule * Strain (injury), an injury to a mu ...

before material failure, ranges from 46% at , 35% at , 32% at , 22% at , 30% at , 36% at , and increases above there.

–H32 hardening

–H34 hardening

–H112 hardening

–H116 hardening

H116 strain hardened 5086, with properties measured at , has yield strength of , ultimate tensile strength of , and elongation of 12%.

Uses

5086 is the preferred hull material for small aluminium

boat A boat is a watercraft of a large range of types and sizes, but generally smaller than a ship, which is distinguished by its larger size, shape, cargo or passenger capacity, or its ability to carry boats. Small boats are typically found on inl ...

s or larger

yacht A yacht is a sailing or power vessel used for pleasure, cruising, or racing. There is no standard definition, though the term generally applies to vessels with a cabin intended for overnight use. To be termed a , as opposed to a , such a pleasu ...

s. Its high strength and good corrosion resistance make it an excellent match for yachting. 5086 has a tendency to undergo

Stress corrosion cracking Stress corrosion cracking (SCC) is the growth of crack formation in a corrosive environment. It can lead to unexpected and sudden failure of normally ductile metal alloys subjected to a tensile stress, especially at elevated temperature. SCC ...

and is not used much in aircraft construction as a result.5xxx Plate information sheet
at www.alcoa.com, accessed October 29, 2006 5086 has been used in vehicle armor, notably in the M113 Armored Personnel Carrier and

M2 Bradley The M2 Bradley, or Bradley IFV, is an American infantry fighting vehicle that is a member of the Bradley Fighting Vehicle family. It is manufactured by BAE Systems Land & Armaments, which was formerly United Defense. The Bradley is designed for ...

Infantry fighting vehicle.

Welding

5086 is often assembled using

arc welding Arc welding is a welding process that is used to join metal to metal by using electricity to create enough heat to melt metal, and the melted metals, when cool, result in a binding of the metals. It is a type of welding that uses a welding powe ...

, typically

MIG Russian Aircraft Corporation "MiG" (russian: Российская самолётостроительная корпорация „МиГ“, Rossiyskaya samolyotostroitel'naya korporatsiya "MiG"), commonly known as Mikoyan and MiG, was a Russi ...

or TIG welding. The newer technique of

Friction stir welding Friction stir welding (FSW) is a solid-state joining process that uses a non-consumable tool to join two facing workpieces without melting the workpiece material. Heat is generated by friction between the rotating tool and the workpiece material ...

has also been successfully applied but is not in common use. Arc welding reduces mechanical properties to no worse than –O hardening condition. For –H116 base material, measured at ambient temperature, yield strength decreases from to and ultimate strength from . The relatively low decrease in ultimate strength (about 10%) is extremely good performance for an aluminium alloy.

References

Aluminium alloy table

{{aluminium alloys Aluminium–magnesium alloys