Overview
Al7075 (AA7075) is one of the highest-strength aluminum alloys available and is widely regarded as the benchmark material for high-performance aerospace and engineering applications. As a member of the 7000 series aluminum family, Al7075 is primarily alloyed with zinc, magnesium, and copper, providing exceptional mechanical strength and excellent fatigue resistance.
Originally developed for aircraft structures, Al7075 is now extensively used in aerospace, defense, motorsports, robotics, tooling, molds, drones, bicycle components, and high-load mechanical assemblies.
Compared with Al6061, Al7075 offers nearly double the yield strength. Compared with Al2024, it provides higher tensile strength but slightly lower fracture toughness.
Material Specification
| Property | Value |
|---|---|
| Alloy Designation | AA7075 |
| Alloy Series | 7000 Series |
| Main Alloying Elements | Zinc (Zn), Magnesium (Mg), Copper (Cu) |
| Material Type | Ultra High-Strength Heat-Treatable Aluminum Alloy |
| Density | 2.81 g/cm³ |
| Standard Forms | Plate, Sheet, Bar, Rod, Tube, Forgings |
Chemical Composition
| Element | Content (%) |
|---|---|
| Aluminum (Al) | Balance |
| Zinc (Zn) | 5.1–6.1 |
| Magnesium (Mg) | 2.1–2.9 |
| Copper (Cu) | 1.2–2.0 |
| Chromium (Cr) | 0.18–0.28 |
| Silicon (Si) | ≤0.40 |
| Iron (Fe) | ≤0.50 |
| Manganese (Mn) | ≤0.30 |
| Titanium (Ti) | ≤0.20 |
| Others | ≤0.15 Total |
Mechanical Properties
Typical T6 Condition
| Property | Value |
|---|---|
| Tensile Strength | 510–572 MPa |
| Yield Strength | 430–503 MPa |
| Elongation | 8–11% |
| Hardness | 150 HB |
| Elastic Modulus | 71.7 GPa |
| Fatigue Strength | 160 MPa |
Typical T651 Condition
| Property | Value |
|---|---|
| Tensile Strength | 540–572 MPa |
| Yield Strength | 470–505 MPa |
| Elongation | 9–11% |
Physical Properties
| Property | Value |
|---|---|
| Density | 2.81 g/cm³ |
| Melting Point | 477–635°C |
| Thermal Conductivity | 130 W/m·K |
| Electrical Conductivity | 33–38% IACS |
| Thermal Expansion Coefficient | 23.6 × 10⁻⁶/K |
| Specific Heat Capacity | 875 J/kg·K |
Corrosion Resistance
| Environment | Performance |
|---|---|
| Atmospheric Exposure | Good |
| Industrial Environment | Good |
| Marine Environment | Fair |
| Salt Spray Environment | Fair |
| Stress Corrosion Resistance | Moderate |
| Chemical Environment | Fair |
Although Al7075 provides exceptional strength, its corrosion resistance is lower than 5000 and 6000 series alloys. Anodizing, chromate conversion coating, or painting is typically recommended.
International Equivalent Grades
| Standard | Equivalent Grade |
|---|---|
| AA (USA) | AA7075 |
| EN (Europe) | EN AW-7075 |
| DIN (Germany) | AlZn5.5MgCu |
| JIS (Japan) | A7075 |
| ISO | AlZn5.5MgCu |
| GB/T (China) | LC4 |
| UNS | A97075 |
Available Tempers
| Temper | Description |
|---|---|
| T6 | Solution Heat Treated & Artificially Aged |
| T651 | Stress Relieved & Artificially Aged |
| T73 | Improved Stress Corrosion Resistance |
| T7351 | Stress Relieved & Overaged |
| O | Annealed |
Typical Applications
Aerospace Industry
- Aircraft Wing Structures
- Aircraft Frames
- Aerospace Fittings
- Structural Brackets
- Aircraft Fasteners
Defense Industry
- Military Equipment
- Weapon System Components
- Tactical Equipment
- UAV Structures
Automotive & Motorsports
- Racing Components
- Suspension Parts
- Chassis Components
- Performance Upgrades
Robotics & Automation
- Robot Arms
- Motion Control Components
- High-Load Frames
- Precision Assemblies
Sporting Equipment
- Bicycle Frames
- Mountain Bike Components
- Climbing Equipment
- Archery Components
Industrial Manufacturing
- Precision Tooling
- Mold Bases
- Fixture Components
- High-Stress Mechanical Parts
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 |
Al7075 is considered one of the best high-strength aluminum alloys for precision CNC machining.
Advantages
Extremely High Strength
Comparable to some low-alloy steels while maintaining aluminum’s lightweight characteristics.
Outstanding Strength-to-Weight Ratio
Provides exceptional performance in aerospace and racing applications.
Excellent Machinability
Suitable for complex precision-machined parts.
High Fatigue Resistance
Performs well in cyclic loading environments.
Heat Treatable
Mechanical properties can be optimized through various aging treatments.
Excellent Dimensional Stability
Ideal for precision engineering applications.
Limitations
Poor Weldability
Generally not recommended for welded structures.
Lower Corrosion Resistance
Requires surface protection in outdoor and marine environments.
Higher Material Cost
More expensive than Al6061, Al5052, and Al6082.
Lower Fracture Toughness Than Al7050
Not always preferred for thick aerospace structures.
Comparison with Other Aluminum Alloys
| Property | Al7075 | Al7050 | Al2024 | Al6061 | Al6082 |
|---|---|---|---|---|---|
| Strength | Extremely High | Extremely High | Very High | High | High |
| Fracture Toughness | Good | Excellent | Excellent | Good | Good |
| Corrosion Resistance | Fair | Good | Fair | Good | Good |
| Stress Corrosion Resistance | Fair | Excellent | Good | Excellent | Good |
| Machinability | Excellent | Excellent | Excellent | Excellent | Excellent |
| Weldability | Poor | Poor | Poor | Good | Good |
| Aerospace Usage | Excellent | Excellent | Excellent | Limited | Limited |
Comparison with Common Engineering Metals
| Material | Density (g/cm³) | Strength | Corrosion Resistance | Weight Advantage |
|---|---|---|---|---|
| Al7075 | 2.81 | Extremely High | Fair | Excellent |
| Al7050 | 2.83 | Extremely High | Good | Excellent |
| Titanium Grade 5 | 4.43 | Extremely High | Excellent | Good |
| Stainless Steel 17-4PH | 7.75 | Very High | Good | Poor |
| Carbon Steel 4340 | 7.85 | Extremely High | Poor | Poor |
| Al6061 | 2.70 | High | Good | Excellent |
Recommended Surface Finishes
- Clear Anodizing
- Black Anodizing
- Hard Anodizing
- Chromate Conversion Coating
- Alodine Coating
- Chemical Film Coating
- Nickel Plating
- Zinc Plating
- Powder Coating
- Epoxy Painting
- Laser Marking
Frequently Asked Questions (FAQ)
What is Al7075 aluminum?
Al7075 is an ultra-high-strength aerospace-grade aluminum alloy widely used in aircraft, motorsports, robotics, and defense applications.
What is Al7075 used for?
Typical applications include:
- Aircraft Structures
- UAV Components
- Racing Parts
- Bicycle Components
- Robotics Equipment
- Precision Tooling
Is Al7075 stronger than Al6061?
Yes.
| Property | Al7075 | Al6061 |
|---|---|---|
| Tensile Strength | Up to 572 MPa | Up to 310 MPa |
| Yield Strength | Up to 505 MPa | Up to 276 MPa |
| Structural Performance | Much Higher | High |
Al7075 is nearly twice as strong as Al6061.
What is the difference between Al7075 and Al7050?
| Property | Al7075 | Al7050 |
|---|---|---|
| Strength | Similar | Similar |
| Corrosion Resistance | Lower | Higher |
| Fracture Toughness | Lower | Higher |
| Aerospace Thick Sections | Good | Better |
Al7050 is generally preferred for critical aerospace structures, while Al7075 is more common in precision machined components.
Is Al7075 suitable for CNC machining?
Yes. Al7075 is one of the most popular aluminum alloys for high-precision CNC machining due to its strength and excellent machinability.
Can Al7075 be welded?
No. Welding is generally not recommended because it significantly reduces mechanical properties.
Does Al7075 anodize well?
Yes. Al7075 responds well to anodizing and hard anodizing for improved wear and corrosion resistance.
Is Al7075 suitable for aerospace applications?
Yes. Al7075 has been widely used in aerospace for decades and remains one of the industry’s preferred high-strength aluminum alloys.
Why is Al7075 called aircraft-grade aluminum?
Because it combines:
- Extremely High Strength
- Lightweight Construction
- Excellent Fatigue Resistance
- Precision Machining Capability
making it ideal for aircraft and high-performance engineering applications.
Does GCNOV provide custom manufacturing services for Al7075?
Yes. GCNOV provides:
- CNC Milling
- CNC Turning
- Aerospace Precision Machining
- Structural Component Manufacturing
- Surface Finishing
- Hard Anodizing
- Prototype Development
- Low-Volume Production
- Mass Production