Aluminum-Lithium Alloys

In a launch vehicle, every kilogram of structure is a kilogram of payload surrendered. That unforgiving arithmetic pushed metallurgists toward an unlikely ally — lithium, the lightest metal on the periodic table — and produced a family of aluminum alloys that flies lighter, stiffer and colder than anything that came before it.

Eata Energy supplies aluminum-lithium raw materials for aerospace research and advanced industrial programs: third-generation grades such as 2195, 2198, 2099, 2199, 2050 and 2060, available as sheet, plate, extrusion, forging stock and powder — the forms that turn low density into real hardware.

Curved fuselage and tank barrel panels — the signature product form of modern aluminum-lithium structures.

What Are Aluminum-Lithium Alloys?

Lithium is a metallurgical bargain. At 0.534 g/cm³ it is the lightest metallic element, and dissolved into aluminum it does two jobs at once: each weight percent of lithium trims roughly 3% from the alloy's density while adding about 6% to its elastic modulus. Strength arrives through fine precipitates — Al₃Li (δ′) and the Al₂CuLi T₁ phase — formed during T8 aging cycles and supported by micro-additions of copper, magnesium, silver and zirconium.

The family took three generations to mature. The second generation (2090, 2091, 8090, carrying 2% lithium or more) chased density aggressively but paid for it with anisotropy and brittle short-transverse behavior. The third generation rebalanced lithium between about 0.75 and 1.8 wt%, exchanging a little density for far better toughness, corrosion performance and manufacturability — and it is this generation, from 2195 and 2198 to 2099, 2050 and 2060, that now builds airliners and rockets. One rule governs all of it: alkali impurities such as sodium and potassium must stay in the single-digit-ppm range, or toughness and ductility collapse. In this alloy family, composition control is not a formality.

Why Designers Reach for Al-Li

• Structural weight down 5–10%. Switching from conventional 2xxx or 7xxx aluminum to Al-Li sheds meaningful mass without changing geometry.
• Stiffness up at the same time. Third-generation grades run elastic moduli of 75–79 GPa — roughly 10% better specific stiffness than 2024-T3 — decisive in buckling-critical skins, struts and panels.
• Strength that grows in the cold. Alloy 2195 delivers about 590 MPa ultimate at room temperature and climbs toward 860 MPa at 20 K; fracture toughness actually improves below −100 °C. Cryogenics rewards this alloy instead of punishing it.
• Slower fatigue crack growth. Third-generation Al-Li resists crack propagation better than legacy 2xxx grades — the fatigue strength of 2195 (~190 MPa) comfortably exceeds that of 2024 (~138 MPa).
• Weldable where it counts. Friction stir welding joins these alloys at high joint efficiency — the very process that builds the 3.66 m diameter propellant tank walls of the Falcon 9 family.
• Flight-proven, repeatedly. The Space Shuttle Super Lightweight External Tank (2195, over 10% lighter than the 2219 tank it replaced), Falcon 9 and Falcon Heavy tank walls (2198), the Orion crew module (2195 spars with 2050 frames and ribs), Atlas V Centaur adapters — the résumé is real and still growing.

Grades in Focus

Extruded T, L and Z sections — stringers and stiffeners ready for airframe and tank structures.

Forms and Tempers We Offer

• Sheet and plate — damage-tolerant and high-strength T8-family tempers, plus thick plate for machined structure.
• Extrusions and profiles — T, L, Z and custom cross-sections for stringers, longerons and frames.
• Forgings and billet — high-integrity stock for machined fittings and brackets.
• Round bar and rod — supplied in cut lengths on request.
• Atomized powders — for additive-manufacturing research and alloy development programs.
• Machined components — produced to drawing from certified aluminum-lithium stock.

Friction stir welding — the joining process that unlocked welded aluminum-lithium tank structures.

Where Aluminum-Lithium Goes to Work

Launch Vehicles and Spacecraft

Cryogenic propellant tanks are this alloy family's defining job. The Space Shuttle's Super Lightweight External Tank flew alloy 2195 from 1998 onward, more than 10% lighter than the tank it replaced; today, friction-stir-welded 2198 forms the 3.66 m diameter tank walls of the Falcon 9 and Falcon Heavy. Orion's crew module rides on 2195 spars with 2050 frames, ribs and window sections, and Centaur hardware on Atlas V carries the same pedigree.

Cryogenic propellant tanks — the application that made aluminum-lithium alloys famous.

Commercial and Military Aircraft

From the wings of the A-5 Vigilante — the first aerospace use of Al-Li — to the lower wing skins of the Airbus A380, the inner wing structure of the A350, the fuselage of the Bombardier CSeries (24% Al-Li by structure), the cargo floor of the Boeing 777X and the fan blades of Pratt & Whitney's PurePower geared turbofan, aluminum-lithium keeps proving that metallic airframes still have room to evolve.

Wing ribs and spars are classic aluminum-lithium territory: stiffness-driven, weight-critical structure.

Motorsport and High-Performance Engineering

Formula One brake calipers and helicopter components — the EH101 among them — exploit the same stiffness-to-weight advantage in far smaller packages, proof that the family scales down as gracefully as it scales up.

Cryogenics and Future Energy Systems

Liquid-hydrogen aviation, reusable launch systems and next-generation cryogenic storage all need materials that grow stronger at 20 K instead of embrittling. Aluminum-lithium is one of the few metallic families that does exactly that.

Research and Alloy Development

Universities and R&D teams work with our sheet, plate and powder stock on friction stir welding development, next-generation compositions and additive manufacturing of Al-Li — programs we support with small-batch, well-characterized material.

Machined fittings and brackets — where certified Al-Li billet turns into finished structure.

Sourcing Al-Li from Eata Energy

• Chemistry controlled to ppm level. Sodium and potassium impurities are the silent killers of Al-Li toughness; our material is verified to hold them in the single-digit-ppm range, with full certificates of analysis.
• Temper you can trust. T8, T851 and related tempers are confirmed by hardness and tensile verification — documented, lot by lot.
• From coupons to production lots. Test panels for process development, or pallet quantities for a build — both are standard requests here.
• Grade-selection support. 2195 or 2198? 2099 or 2199? Tell us the loading case, temperature range and joining route, and we will walk through the trade-offs with you.

Custom Aluminum-Lithium Solutions

Non-standard gauges and widths, unusual tempers, custom extrusion dies, cut-to-size blanks, powders with specified size distributions, machined parts to drawing, even small development melts for experimental compositions — if it involves aluminum-lithium, it is worth a conversation. Send us your specification or your service conditions, and Eata Energy will respond with a material proposal and a quotation built around your program.

For Research or Industrial Raw Materials, Not For Personal Medical Use!