5086 aluminium alloy

Basic properties

5086 has a density of 2.660 kg/dm3, with a specific gravity of 2.66.

Melting point is 590 °C.

Chemical properties

The alloy composition of 5086 is:

• Chromium - 0.05%–0.25% by weight
• Copper - 0.1% maximum
• Iron - 0.5% maximum
• Magnesium - 3.5%–4.5%
• Manganese - 0.2%–0.7%
• Silicon - 0.4% maximum
• Titanium - 0.15% maximum
• Zinc - 0.25% maximum
• Others each 0.05% maximum
• Others total 0.15% maximum
• Remainder Aluminium

Mechanical properties

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

–O hardening

Unhardened 5086 has a yield strength of 17 ksi and ultimate tensile strength of 38 ksi from -28 to. At cryogenic temperatures it is slightly stronger: at -196 °C, yield of 19 ksi and ultimate tensile strength of 55 ksi; above 100 °C its strength is reduced.

Elongation, the strain before material failure, ranges from 46% at -196 °C, 35% at -80 °C, 32% at -28 °C, 22% at 20 °C, 30% at 24 °C, 36% at 100 °C, and increases above there.

–H32 hardening

H32 strain hardened 5086, with properties measured at 20 °C, has yield strength of 28.3 ksi, ultimate tensile strength of 30.1 ksi, and elongation of 6-12%.

–H34 hardening

–H112 hardening

–H116 hardening

H116 strain hardened 5086, with properties measured at 20 °C, has yield strength of 30 ksi, ultimate tensile strength of 42 ksi, and elongation of 12%.

Uses

5086 is the preferred hull material for small aluminium boats or larger yachts. Its high strength and good corrosion resistance make it an excellent match for yachting.

5086 has a tendency to undergo Stress corrosion cracking and is not used much in aircraft construction as a result.

5086 has been used in vehicle armor, notably in the M113 Armored Personnel Carrier and M2 Bradley Infantry fighting vehicle.

Welding

5086 is often assembled using arc welding, typically MIG or TIG welding. The newer technique of Friction stir welding 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 20 °C ambient temperature, yield strength decreases from 30 ksi to 17 ksi and ultimate strength from 42 to. The relatively low decrease in ultimate strength (about 10%) is extremely good performance for an aluminium alloy.

References

Aluminium alloy table

References

1. '''Boatbuilding with Aluminum''', Stephen F. Pollard, 1993, {{ISBN. 978-0-07-050426-4
2. [http://www.suppliersonline.com/propertypages/5086.asp 5086 Material properties] at supplliersonline.com, accessed October 29, 2006
3. [http://www.alcoa.com/mill_products/catalog/pdf/general_engineering_plates/en/5xxx_EN.pdf 5xxx Plate information sheet] {{Webarchive. link. (2006-10-26 at www.alcoa.com, accessed October 29, 2006)