Forming
Form in T3/T4 or solution-treated condition, then age. Some 8090 variants were developed for superplastic forming of complex panels.
Aluminium-lithium aerospace sheet
8090 Aluminium-Lithium Sheet & Plate
8090 is a second-generation aluminium-lithium alloy with about 2.4 % lithium, 1.3 % copper and 1 % magnesium. Lithium lowers density to about 2.55 g/cm³ and raises stiffness by around 10 %, so 8090 parts weigh noticeably less than 2024 or 7075 equivalents. Metline sources 8090 sheet to AMS 4259 and plate to customer specifications for aerospace buyers worldwide.
- Alloy
- Al-Li-Cu-Mg-Zr
- Density
- About 2.55 g/cm³
- Tempers
- T6, T81, T8771
- Sheet standard
- AMS 4259 (8090-T6)
What is 8090 aluminium-lithium?
Lithium is the lightest metal. Every 1 % of lithium added to aluminium cuts density by about 3 % and raises the elastic modulus by about 6 %. 8090 uses roughly 2.4 % lithium, so it is around 8 – 10 % lighter and about 10 % stiffer than conventional 2xxx and 7xxx aerospace alloys.
8090 was developed in Europe in the 1980s as a drop-in replacement for 2024 and 7075 in skins, frames and stringers. It flew on helicopter and military aircraft programmes, but its anisotropy, low short-transverse toughness and high cost limited wider use. Third-generation Al-Li alloys such as 2050, 2195, 2196 and 2099, with lower lithium and better toughness, have since taken over most new designs.
Today 8090 is mainly bought for existing platforms, repairs, spares and research. Availability is limited and material is often supplied from specific mill runs, so early enquiry is important.
8090 chemical composition (wt %)
| Element | Minimum | Maximum | Role |
|---|---|---|---|
| Lithium (Li) | 2.2 | 2.7 | Lowers density, raises modulus, forms Al3Li (δ′) precipitates |
| Copper (Cu) | 1.0 | 1.6 | Forms T1 (Al2CuLi) and S′ phases, adds strength |
| Magnesium (Mg) | 0.6 | 1.3 | Solid-solution and S′ (Al2CuMg) strengthening |
| Zirconium (Zr) | 0.04 | 0.16 | Keeps the structure unrecrystallised |
| Silicon (Si) | — | 0.20 | Impurity |
| Iron (Fe) | — | 0.30 | Impurity |
| Manganese (Mn) | — | 0.10 | Impurity |
| Chromium (Cr) | — | 0.10 | Impurity |
| Zinc (Zn) | — | 0.25 | Impurity |
| Titanium (Ti) | — | 0.10 | Grain refiner |
| Aluminium (Al) | Remainder |
Limits as registered with the Aluminum Association and in EN 573-3 for EN AW-8090.
8090 tempers and properties
8090 is strengthened by ageing, and a small stretch before ageing (the "8" in T8 tempers) helps nucleate the copper-bearing phases evenly. The figures below are indicative published values for comparison; design to the minimums in the order specification.
| Temper / form | Purpose | Tensile (indicative) | Yield (indicative) | Elongation |
|---|---|---|---|---|
| T81 sheet | Damage-tolerant skins, 2024-T3 replacement | 400 – 440 MPa | 320 – 350 MPa | 8 – 11 % |
| T6 sheet (AMS 4259, unrecrystallised) | Medium/high-strength sheet | 450 – 480 MPa | 350 – 400 MPa | 6 – 8 % |
| T8771 plate | Medium/high-strength plate, 7075-T7351 replacement | 460 – 500 MPa | 400 – 430 MPa | 4 – 6 % |
| T3 / T4 | Forming condition before final ageing | Lower | Lower | Higher |
Physical properties
- Density
- About 2.54 – 2.55 g/cm³ (0.092 lb/in³)
- Modulus of elasticity
- About 77 – 80 GPa
- Melting range
- About 600 – 655 °C
- Thermal expansion
- About 21 – 22 µm/m·°C
- Specific stiffness
- Roughly 15 – 20 % higher than 2024 or 7075
Supply range and standards
8090 supply
- Sheet
- About 1 – 6 mm, T6 to AMS 4259 or T81 to customer specification
- Plate
- Thicker gauges in T8771 or T651-type tempers on enquiry
- Sizes
- Confirmed per mill run; cut-to-size blanks available
- Standards
- AMS 4259 (sheet, 8090-T6); EN 573-3 chemistry (EN AW-8090); aerospace prime specifications
- Testing
- Chemistry, tensile in L and LT directions, optional fracture toughness and ultrasonic inspection
Forming, machining and joining
Machining
Similar to 2024; keep swarf separate from other alloys, because lithium-bearing scrap must be recycled separately.
Joining
Usually riveted. Fusion welding is possible with careful surface preparation to avoid porosity, but is rarely used on airframes.
Anisotropy
Properties vary noticeably with direction, and short-transverse toughness is low. Orient parts so that the main load lies in the rolling direction.
Corrosion
Generally comparable to 2024; protect with conversion coatings, primers and paint as normal for airframe parts.
Swarf safety
Fine Al-Li chips are reactive; store dry and handle under normal light-metal fire precautions.
Applications of 8090
- Fuselage skins, frames and stringers on helicopters and military aircraft
- Wing leading edges and secondary structures where stiffness limits design
- Spacecraft and satellite structures needing high specific stiffness
- Spares and repair material for platforms originally built in 8090
8090 compared with other Al-Li and conventional alloys
| Property | 8090 | 2090 | 2195 | 2024-T3 |
|---|---|---|---|---|
| Lithium content | ~2.4 % | ~2.2 % | ~1.0 % | — |
| Density | ~2.55 g/cm³ | ~2.59 g/cm³ | ~2.71 g/cm³ | 2.78 g/cm³ |
| Modulus | ~77 – 80 GPa | ~76 GPa | ~76 GPa | 73 GPa |
| Main use | Helicopter and fighter airframes | Airframe plate and extrusions | Launch vehicle tanks | General airframe |
How to order 8090
- SpecifyAlloy and temper, thickness, width and length, quantity and the governing specification with its revision (AMS 4259 or prime specification).
- ConfirmWe confirm the specification can be met, the tolerance class, any extra tests and the delivery terms (EXW, FOB, CIF or DAP).
- InspectMaterial is checked for dimensions, straightness and surface condition; tests named on the order are carried out or arranged with a third party.
- DocumentEach lot ships with a mill test certificate to EN 10204 3.1 showing chemistry and mechanical results, traceable to the cast or lot number.
- Pack and shipExport packing in sealed, moisture-protected wooden cases, coils on pallets or reels, shipped by sea or air to your port or door.
References and standards
- SAE AMS 4259 – Aluminum Alloy, Sheet 2.4Li-1.3Cu-0.95Mg-0.10Zr (8090-T6), Solution and Precipitation Heat Treated (Unrecrystallized)
- EN 573-3 – Aluminium and aluminium alloys: chemical composition and form of wrought products
- The Aluminum Association – International Alloy Designations and Chemical Composition Limits (Teal Sheets)
- ASM Handbook, Vol. 2 – Properties and Selection: Nonferrous Alloys and Special-Purpose Materials
8090 aluminium-lithium (aluminum) sheet: frequently asked questions
What is the density of 8090?
About 2.54 – 2.55 g/cm³, roughly 8 – 10 % lower than 2024 or 7075.
Is 8090 still used on new aircraft?
Rarely. New designs mostly use third-generation Al-Li alloys such as 2050, 2195, 2196 and 2099. 8090 is mainly bought for existing platforms, spares and research.
What does AMS 4259 cover?
Sheet in 8090-T6, solution and precipitation heat treated, with an unrecrystallised structure.
Can 8090 be welded?
It can be fusion welded with careful preparation, but porosity is a risk and airframe parts are normally riveted.
Does 8090 scrap need special handling?
Yes. Lithium-bearing scrap must be kept separate from other aluminium scrap so it can be recycled correctly.
Need 8090 or another Al-Li alloy?
Send your specification and sizes. We will confirm availability, or suggest a current Al-Li alternative.
