EN AW-7075 vs EN AW-2024 Aluminum Alloy Comparison
In the realm of high-strength aluminum alloys, EN AW-7075 and EN AW-2024 are among the most widely utilized. Renowned for their outstanding mechanical performance and reliable manufacturability, these alloys are commonly applied in aerospace, automotive, mold making, military, and high-performance structural components.
This guide provides a comprehensive comparison of EN AW-7075 and EN AW-2024, examining chemical composition, mechanical properties, corrosion resistance, weldability, machinability, and practical applications, to help engineers, manufacturers, and buyers select the most suitable material for their projects.
I. Overview of EN AW-7075 and EN AW-2024
EN AW-7075 Aluminum Alloy
EN AW-7075 is a high-strength aluminum-zinc-magnesium-copper alloy belonging to the 7xxx series. Zinc is the primary alloying element, with magnesium and copper providing additional reinforcement. Known for its exceptional strength-to-weight ratio, 7075 is ideal for aerospace structural frames, racing components, bicycles, and defense applications where maximum strength and stiffness are essential.
EN AW-2024 Aluminum Alloy
EN AW-2024 is part of the 2xxx aluminum-copper alloy series, where copper is the main strengthening element, supported by magnesium and manganese. It combines high strength with excellent fatigue resistance, making it suitable for aircraft fittings, fuselage structures, and automotive suspension systems.
II. Chemical Composition Comparison
| Alloy | Major Alloying Elements (wt %) |
|---|---|
| EN AW-7075 | Zn: 5.1–6.1%, Mg: 2.1–2.9%, Cu: 1.2–2.0%, Cr: 0.18–0.28% |
| EN AW-2024 | Cu: 3.8–4.9%, Mg: 1.2–1.8%, Mn: 0.3–0.9%, Fe: ≤0.5% |
Insight:
7075 relies on zinc for superior strength, while 2024 depends on copper for both strength and fatigue resistance. Consequently, 7075 excels under static loads, whereas 2024 is better suited for cyclic or dynamic loads.
III. Mechanical Properties Comparison (T6 Temper)
| Property | EN AW-7075-T6 | EN AW-2024-T6 |
|---|---|---|
| Ultimate Tensile Strength (MPa) | 510–580 | 450–490 |
| Yield Strength (MPa) | 430–500 | 320–420 |
| Elongation (%) | 5–11 | 10–20 |
| Elastic Modulus (GPa) | 71.7 | 73.1 |
| Hardness (HB) | 150–160 | 120–135 |
Analysis:
EN AW-7075 offers significantly higher strength, making it ideal for high-stress structural components. EN AW-2024 provides greater ductility and fatigue resistance, which is advantageous for components subjected to repeated loading cycles.
IV. Corrosion Resistance
EN AW-7075: Susceptible to stress corrosion and pitting due to high copper content. Requires protective coatings for use in marine or humid environments.
EN AW-2024: Also has relatively low corrosion resistance but slightly better performance than 7075 under fatigue-corrosive conditions.
Conclusion:
Both alloys benefit from surface treatments like anodizing, painting, or sealing to enhance long-term durability.
V. Weldability and Machinability
| Property | EN AW-7075 | EN AW-2024 |
|---|---|---|
| Weldability | Poor-prone to cracking | Very poor-generally not recommended |
| Machinability | Excellent | Excellent |
| Cold Formability | Moderate to poor | Good |
| Hot Formability | Limited, risk of cracking | Good with proper heat treatment |
Analysis:
Both alloys are highly machinable, particularly for CNC processes. Welding is not recommended, especially for 2024, due to high hot-cracking risk. For welded assemblies, consider alloys from the 6xxx or 5xxx series instead.
VI. Typical Applications
| Industry | EN AW-7075 Applications | EN AW-2024 Applications |
|---|---|---|
| Aerospace | Spars, wing ribs, landing gear components | Fuselage skins, wing ribs, fasteners |
| Automotive & Racing | Suspension arms, chassis brackets, engine mounts | Body frames, strut mounts |
| Mold Making | High-strength mold bases and fixtures | Stamping dies, aircraft molds |
| Sporting Goods | Bicycle frames, trekking poles, ski bindings | Archery parts, model aircraft components |
| Defense | Firearm bodies, stocks, ammunition casings | Missile parts, launcher components |
Conclusion:
EN AW-7075 is suited for high-load, static strength applications.
EN AW-2024 is better for fatigue-sensitive, dynamic structures requiring good formability.
VII. How to Choose Between EN AW-7075 and EN AW-2024
| Use Case | Recommended Alloy | Reason |
|---|---|---|
| High-strength, lightweight structures | EN AW-7075 | Superior strength-to-weight ratio |
| Components under cyclic fatigue | EN AW-2024 | Better fatigue resistance and ductility |
| Welded assemblies | Neither (use 6xxx or 5xxx series) | Poor weldability for both alloys |
| Harsh/corrosive environments | Either, with surface treatment | Requires anodizing or coating |
VIII. Final Thoughts
EN AW-7075 and EN AW-2024 are among the most capable high-performance aluminum alloys. While both share excellent machinability and high strength, their unique characteristics make them better suited to specific applications:
Choose EN AW-7075 for maximum strength and stiffness, such as in aerospace structures and racing components.
Choose EN AW-2024 for enhanced fatigue resistance, ductility, and formability, ideal for dynamically loaded parts.
Both alloys require surface protection due to limited corrosion resistance. Selecting the right alloy based on application demands, manufacturing process, and environmental exposure ensures optimal performance and cost-effectiveness.
