Introduction
2219 aluminum is the 2xxx-series alloy built for temperature extremes — it holds strength at cryogenic temperatures and retains useful mechanical properties at elevated temperatures up to 315°C, a range where most aluminium alloys soften significantly. Originally developed for aerospace fuel tanks and high-temperature structures, 2219 also stands out as one of the few 2xxx alloys that welds reliably. This guide maps where the alloy works, where the limits are, and how to compare it against 2024, 7075, and 6061.
Composition chimique
2219 is an Al-Cu-Mn system with small additions of titanium, vanadium, and zirconium for grain refinement and high-temperature stability:
- Copper: 5.8–6.8%
- Manganese: 0.2–0.4%
- Iron: ≤0.3%
- Silicon: ≤0.2%
- Titanium: 0.02–0.1%
- Vanadium: 0.05–0.15%
- Zirconium: 0.1–0.25%
- Zinc: ≤0.1%
- Balance: Aluminum
Propriétés principales
Strength and Elevated-Temperature Performance
In the T62 temper, 2219 reaches tensile strengths around 414–455 MPa with yield strength in the 290–345 MPa range. The defining advantage over 2024 and 7075 is retained strength at elevated temperature — 2219 maintains useful mechanical properties above 250°C, where both 2024 and 7075 drop steeply. At cryogenic temperatures, tensile and yield strength increase without a corresponding loss in toughness.
Résistance à la rupture
2219 delivers high fracture toughness in the T62 and T87 tempers — a critical property for aerospace pressure vessels and cryogenic tank structures. The alloy resists crack propagation better than most 7000-series alloys at equivalent strength levels.
Soudabilité
2219 is one of the few 2xxx-series alloys rated as weldable. GTAW (TIG) and GMAW (MIG) are the standard processes. Filler metal 2319 is recommended to match the base metal composition. Post-weld re-heat-treatment is typically required to restore full strength in the weld zone.
Résistance à la corrosion
Like most 2xxx alloys, bare 2219 has limited corrosion resistance due to the high copper content. Cladding or protective coating is standard for outdoor or corrosive service. Exfoliation corrosion resistance improves in the T87 and T851 tempers through controlled grain structure.
2219 vs. Other Alloys
2219 vs. 2024
2024 delivers higher room-temperature strength (~470 MPa UTS in T4) and is the default aerospace sheet alloy. 2219 sacrifices some room-temperature strength for elevated-temperature performance and weldability — the deciding factor is whether the part operates above 150°C or requires fusion welding.
2219 vs. 7075
7075-T6 has higher room-temperature strength (~570 MPa UTS) but is not recommended for fusion welding. 2219 wins when weldability, high-temperature strength retention, or cryogenic toughness are the critical factors. 7075 wins when peak room-temperature strength-to-weight ratio is the only requirement.
2219 vs. 6061
6061 is weldable, corrosion-resistant, and widely available at lower cost, but its elevated-temperature performance is limited and strength is significantly lower (~310 MPa UTS in T6). 2219 is the choice when the service temperature range pushes past 6061’s practical limit.
Tempéraments courants
- T62: Solution heat-treated and artificially aged. The most widely used temper for general aerospace applications.
- T87: Solution heat-treated, cold-worked, and artificially aged. Provides higher strength and better stress-corrosion resistance — preferred for structural and pressure-vessel applications.
- T851: Solution heat-treated, stress-relieved by stretching, and artificially aged. Selected when residual stress control is needed for precision-machined parts.
Go/No-Go Limits
Use this quick reference to decide whether 2219 fits your application.
Go — use 2219 when:
- The part will operate in a wide temperature range, from cryogenic to 250°C or beyond — 2219 retains strength better at both extremes than 2024 or 7075. Typical applications: aerospace fuel tanks, cryogenic storage vessels, rocket components.
- Fusion welding is required and room-temperature strength above 400 MPa is still needed — 2219 is weldable with filler 2319, unlike most other 2xxx and 7xxx alloys. Typical applications: welded pressure vessels, structural aerospace weldments.
- High fracture toughness at strength levels above 400 MPa is a specification requirement — 2219-T87 resists crack propagation better than 7075-T6.
No-Go — do not use 2219 when:
- Peak room-temperature strength is the only criterion — 2024-T3 or 7075-T6 offer higher UTS at lower cost and wider availability.
- Corrosion resistance in the bare (unclad) condition is required — cladding or protective coating is mandatory for 2219 in corrosive environments.
- General fabrication work with standard aluminum tooling is the full scope — 6061-T6 covers most structural and general-engineering applications at a lower material cost.
- The specification calls for high-volume production with fast turnaround — 2219 is a specialty alloy with narrower stock availability; verify lead time before committing.
Applications
The Go/No-Go criteria above cover selection logic. The list below maps specific systems where 2219 is standard practice:
- Aerospace — fuel tanks, pressure vessels, fuselage frames, wing structures
- Space — cryogenic tank structures, rocket components, launch vehicle structural parts
- Defense — armor plate, structural weldments, high-temperature components
- Industrial — high-temperature tooling, heat-exchanger components, welded structural assemblies
Conclusion
2219 aluminum is the 2xxx alloy built for temperature extremes — it holds strength where 2024 and 7075 soften, and it welds where most other high-strength grades crack. The trade-offs are higher cost, narrower stock availability, and a mandatory need for cladding or coating in corrosive service.
Linsy Aluminum stocks 2219 plate, bar, and custom-extruded profiles, with low-MOQ custom production available for non-stock dimensions. Full MTC documentation comes with every order, and SGS testing for chemical composition, mechanical properties, and ultrasonic inspection is available on request. Send the drawing for a grade-fit and lead-time review.
Questions fréquemment posées
How does 2219 perform at cryogenic temperatures?
2219 shows increased tensile and yield strength at cryogenic temperatures without a corresponding loss in toughness — one of the reasons it was selected for the Space Shuttle external tank. Both strength and fracture toughness improve as temperature drops, making it a strong candidate for LNG, liquid oxygen, and liquid hydrogen storage systems.
Can 2219 be welded, and what filler is recommended?
Yes — 2219 is weldable via GTAW (TIG) and GMAW (MIG). Filler metal 2319 is recommended to match the base metal chemistry. Post-weld re-heat-treatment is typically required to restore mechanical properties in the weld zone. Qualification testing with production-intent parameters is recommended.
What is the main advantage of 2219 over 2024?
Elevated-temperature strength retention and weldability. 2024 has higher room-temperature strength but softens significantly above 150°C and is not recommended for fusion welding. 2219 is the answer when the part will see heat or needs to be welded.
Is 2219 available in sheet form?
2219 is primarily produced as plate, bar, forging stock, and extrusion. Sheet may be available depending on temper and thickness — for sheet-specific requirements, confirm availability with the supplier, including any minimum order quantity and lead time.
Does 2219 require special heat treatment after machining?
The T62, T87, and T851 tempers are supplied in the aged condition and generally do not require post-machining heat treatment. However, if welding is involved, re-heat-treatment of the weld zone is standard practice to restore strength. Confirm the required temper and post-process treatment with the mill before ordering.
