Overview
Al7050 (AA7050) is a high-strength, heat-treatable aluminum alloy belonging to the 7000 series aluminum family. Alloyed primarily with zinc, copper, and magnesium, Al7050 was specifically developed for aerospace applications requiring exceptional strength, excellent fracture toughness, superior stress corrosion cracking resistance, and high fatigue performance.
Compared with Al7075, Al7050 offers better stress corrosion resistance, improved toughness in thick sections, and enhanced performance in critical aerospace structures. It is widely used in aircraft wing structures, fuselage frames, bulkheads, landing gear components, and military applications.
Today, Al7050 is considered one of the premium aerospace-grade aluminum alloys available.
Material Specification
| Property | Value |
|---|---|
| Alloy Designation | AA7050 |
| Alloy Series | 7000 Series |
| Main Alloying Elements | Zinc (Zn), Copper (Cu), Magnesium (Mg) |
| Material Type | Aerospace High-Strength Aluminum Alloy |
| Density | 2.83 g/cm³ |
| Standard Forms | Plate, Bar, Forgings, Extrusions |
Chemical Composition
| Element | Content (%) |
|---|---|
| Aluminum (Al) | Balance |
| Zinc (Zn) | 5.7–6.7 |
| Copper (Cu) | 2.0–2.6 |
| Magnesium (Mg) | 1.9–2.6 |
| Zirconium (Zr) | 0.08–0.15 |
| Silicon (Si) | ≤0.12 |
| Iron (Fe) | ≤0.15 |
| Manganese (Mn) | ≤0.10 |
| Chromium (Cr) | ≤0.04 |
| Others | ≤0.15 Total |
Mechanical Properties
Typical T7451 Condition
| Property | Value |
|---|---|
| Tensile Strength | 510–570 MPa |
| Yield Strength | 440–505 MPa |
| Elongation | 8–12% |
| Hardness | 150 HB |
| Elastic Modulus | 71.7 GPa |
| Fatigue Strength | 155 MPa |
Typical T7651 Condition
| Property | Value |
|---|---|
| Tensile Strength | 525–580 MPa |
| Yield Strength | 455–515 MPa |
| Fracture Toughness | Excellent |
Physical Properties
| Property | Value |
|---|---|
| Density | 2.83 g/cm³ |
| Melting Point | 477–635°C |
| Thermal Conductivity | 130–155 W/m·K |
| Electrical Conductivity | 35–40% IACS |
| Thermal Expansion Coefficient | 23.5 × 10⁻⁶/K |
| Specific Heat Capacity | 870 J/kg·K |
Corrosion Resistance
| Environment | Performance |
|---|---|
| Atmospheric Exposure | Good |
| Industrial Environment | Good |
| Marine Environment | Fair |
| Salt Spray Environment | Fair |
| Stress Corrosion Resistance | Excellent |
| Exfoliation Corrosion Resistance | Excellent |
Al7050 was specifically designed to provide significantly improved stress corrosion cracking resistance compared to earlier 7000 series alloys such as Al7075.
International Equivalent Grades
| Standard | Equivalent Grade |
|---|---|
| AA (USA) | AA7050 |
| EN (Europe) | EN AW-7050 |
| DIN (Germany) | AlZn6CuMgZr |
| ISO | AlZn6CuMgZr |
| AMS Aerospace Standard | AMS 4050 / AMS 4201 |
| GB/T (China) | 7050 |
| UNS | A97050 |
Available Tempers
| Temper | Description |
|---|---|
| T7451 | Stress Corrosion Resistant Plate |
| T74511 | Extrusion Temper |
| T7651 | High Strength Stress Relieved |
| T73651 | Enhanced Corrosion Resistance |
| O | Annealed |
Typical Applications
Aerospace Industry
- Aircraft Wing Structures
- Fuselage Frames
- Bulkheads
- Wing Skins
- Wing Spars
- Aircraft Structural Components
Defense Industry
- Military Aircraft
- Missile Structures
- Defense Equipment
- Tactical Systems
Aviation Manufacturing
- Landing Gear Components
- Structural Forgings
- Aerospace Fasteners
- High-Stress Assemblies
High-Performance Engineering
- Structural CNC Components
- Precision Aerospace Parts
- Load-Bearing Assemblies
Machining Characteristics
| Manufacturing Process | Rating |
|---|---|
| CNC Milling | Excellent |
| CNC Turning | Excellent |
| Drilling | Excellent |
| Tapping | Excellent |
| Threading | Excellent |
| High-Speed Machining | Excellent |
| Forging | Excellent |
| Welding | Poor |
| Anodizing | Excellent |
Al7050 is widely used for aerospace CNC machining due to its high strength, dimensional stability, and excellent machinability.
Advantages
Extremely High Strength
One of the strongest aerospace aluminum alloys available.
Excellent Fracture Toughness
Performs exceptionally well under high-stress conditions.
Superior Stress Corrosion Resistance
Significantly better than Al7075.
Excellent Fatigue Performance
Suitable for cyclic loading applications.
Heat Treatable
Mechanical properties can be optimized through advanced aging treatments.
Excellent Machinability
Ideal for precision aerospace manufacturing.
Limitations
Poor Weldability
Generally not recommended for welded structures.
Higher Material Cost
More expensive than 6000 and 5000 series alloys.
Moderate General Corrosion Resistance
Requires protective finishing in harsh environments.
Limited Formability
Not suitable for deep drawing or complex sheet metal forming.
Comparison with Other Aluminum Alloys
| Property | Al7050 | Al7075 | Al2024 | Al6061 | Al6082 |
|---|---|---|---|---|---|
| Strength | Extremely High | Extremely High | Very High | High | High |
| Fracture Toughness | Excellent | Good | Excellent | Good | Good |
| Stress Corrosion Resistance | Excellent | Fair | Good | Excellent | Good |
| Machinability | Excellent | Excellent | Excellent | Excellent | Excellent |
| Weldability | Poor | Poor | Poor | Good | Good |
| Aerospace Usage | Excellent | Excellent | Excellent | Limited | Limited |
| Cost | Very High | High | High | Medium | Medium |
Comparison with Common Engineering Metals
| Material | Density (g/cm³) | Strength | Corrosion Resistance | Aerospace Suitability |
|---|---|---|---|---|
| Al7050 | 2.83 | Extremely High | Good | Excellent |
| Al7075 | 2.81 | Extremely High | Fair | Excellent |
| Al2024 | 2.78 | Very High | Fair | Excellent |
| Titanium Grade 5 | 4.43 | Extremely High | Excellent | Excellent |
| Stainless Steel 17-4PH | 7.75 | Very High | Good | Good |
| Carbon Steel 4340 | 7.85 | Extremely High | Poor | Limited |
Recommended Surface Finishes
- Clear Anodizing
- Hard Anodizing
- Sulfuric Acid Anodizing
- Chromate Conversion Coating
- Alodine Coating
- Chemical Film Coating
- Nickel Plating
- Zinc Plating
- Epoxy Primer
- Aerospace Paint Systems
- Laser Marking
Frequently Asked Questions (FAQ)
What is Al7050 aluminum?
Al7050 is a premium aerospace-grade aluminum alloy designed for high-strength structural applications requiring excellent toughness and stress corrosion resistance.
What is Al7050 used for?
Typical applications include:
- Aircraft Wings
- Fuselage Structures
- Bulkheads
- Landing Gear Components
- Aerospace Forgings
- Military Aircraft Structures
Is Al7050 stronger than Al7075?
Strength is similar, but Al7050 generally provides:
- Better Fracture Toughness
- Better Stress Corrosion Resistance
- Better Thick-Section Performance
What is the difference between Al7050 and Al7075?
| Property | Al7050 | Al7075 |
|---|---|---|
| Strength | Similar | Similar |
| Fracture Toughness | Higher | Lower |
| Stress Corrosion Resistance | Better | Lower |
| Aerospace Structures | Preferred | Common |
Is Al7050 suitable for CNC machining?
Yes. Al7050 is widely used in aerospace CNC machining due to its excellent machinability and dimensional stability.
Can Al7050 be welded?
No. Like most 7000 series alloys, Al7050 is generally not recommended for welding.
Does Al7050 anodize well?
Yes. Al7050 can be anodized and is commonly used with aerospace-approved surface treatments.
Why is Al7050 used in aircraft structures?
Because it combines:
- Extremely High Strength
- Excellent Fracture Toughness
- Superior Stress Corrosion Resistance
- Lightweight Performance
making it ideal for critical aerospace structures.
Is Al7050 better than Al2024?
For high-strength structural applications, yes. Al7050 generally offers higher strength and better corrosion resistance.
Does GCNOV provide custom manufacturing services for Al7050?
Yes. GCNOV provides:
- CNC Milling
- CNC Turning
- Aerospace Precision Machining
- Structural Component Manufacturing
- Surface Finishing
- Hard Anodizing
- Prototype Development
- Low-Volume Production
- Mass Production