In the aerospace and defense industries, where every gram matters and performance cannot be compromised, the choice of material plays a defining role in ensuring both safety and efficiency. Among the wide range of high-strength aluminum alloys, the Aircraft Grade Aluminum 7175 Sheet stands out as a material that perfectly balances superior strength, lightweight performance, and excellent fatigue resistance.
As an advanced derivative of the 7000 series aluminum alloys, Aluminum 7175 offers higher strength-to-weight ratio, outstanding toughness, and exceptional corrosion resistance, making it an ideal choice for aircraft structures, aerospace fasteners, and military-grade components.
This article explores the superior strength and lightweight advantage of Aircraft Grade Aluminum 7175 Sheet, its mechanical and physical properties, production process, and key applications across industries — along with how SASAALUMINUM delivers world-class quality and consistency for global aerospace standards.
Introduction to Aluminum Alloy 7175
Aluminum Alloy 7175 is a high-strength, heat-treatable aluminum-zinc alloy, developed specifically for aerospace-grade applications where superior mechanical performance is required. It belongs to the 7000 series of aluminum alloys (Al-Zn-Mg-Cu system), which are known for their exceptional strength, machinability, and durability.
What distinguishes 7175 from other 7000-series alloys, such as 7075, is its optimized composition and controlled processing, which result in improved fracture toughness and stress-corrosion resistance, particularly in the T7351 temper.
Compared with other structural metals like steel or titanium, Aircraft Grade Aluminum 7175 Sheet offers a remarkable weight advantage — being nearly three times lighter than steel while maintaining comparable tensile strength. This makes it one of the most efficient materials for load-bearing aerospace applications.
Chemical Composition of Aluminum 7175
| Element | Content (%) | Function |
|---|---|---|
| Zinc (Zn) | 5.6 – 6.1 | Provides high strength through precipitation hardening |
| Magnesium (Mg) | 2.3 – 2.9 | Enhances strength and hardness |
| Copper (Cu) | 1.2 – 1.9 | Improves machinability and contributes to aging response |
| Chromium (Cr) | 0.18 – 0.28 | Increases corrosion resistance and toughness |
| Iron (Fe) | ≤ 0.20 | Controlled impurity |
| Silicon (Si) | ≤ 0.10 | Controlled impurity for machinability |
| Manganese (Mn) | ≤ 0.10 | Improves ductility |
| Titanium (Ti) | ≤ 0.06 | Grain refinement during processing |
| Aluminum (Al) | Balance | Base metal providing low density and high corrosion resistance |
The balanced addition of zinc, magnesium, and copper allows Aluminum 7175 Sheet to achieve an ideal combination of ultra-high strength and excellent structural integrity.
Mechanical Properties of Aircraft Grade Aluminum 7175 Sheet
| Property | Typical Value (T7351 Temper) |
|---|---|
| Tensile Strength | 510 – 570 MPa |
| Yield Strength | 440 – 500 MPa |
| Elongation | 7 – 11% |
| Density | 2.81 g/cm³ |
| Hardness | 155 – 170 HB |
| Modulus of Elasticity | 71 GPa |
| Fatigue Strength | 160 – 180 MPa |
| Operating Temperature | -50°C to 120°C |
Key Mechanical Advantages
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High Tensile and Yield Strength
The 7175 alloy offers mechanical strength comparable to steel while maintaining a much lower weight, which significantly improves aircraft efficiency and load capacity. -
Excellent Fatigue Resistance
Designed for cyclic loading conditions, 7175 aluminum exhibits exceptional fatigue life, ensuring durability in wings, fuselage joints, and fastener components. -
Outstanding Toughness and Ductility
Even under stress and vibration, the alloy maintains its toughness, reducing the risk of crack propagation. -
Superior Machinability
The controlled alloying and fine grain structure make it easy to machine and fabricate while maintaining dimensional accuracy — ideal for precision aerospace parts.
The Lightweight Advantage: Strength-to-Weight Ratio
One of the most critical performance indicators in aerospace materials is the strength-to-weight ratio. For every kilogram of material used in an aircraft, there is a direct impact on fuel efficiency, payload capacity, and operational cost.
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Density of Aluminum 7175: 2.81 g/cm³
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Density of Steel: ~7.85 g/cm³
This means Aircraft Grade Aluminum 7175 Sheet is almost three times lighter than steel, while achieving nearly the same tensile strength levels as structural steel (500–600 MPa).
This outstanding strength-to-weight ratio leads to:
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Reduced aircraft weight and improved fuel economy
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Enhanced maneuverability and speed in aviation and defense applications
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Lower overall maintenance costs due to corrosion resistance and fatigue durability
In short, Aluminum 7175 Sheet provides the ultimate lightweight solution for applications where performance, reliability, and efficiency must align.
Heat Treatment and Strength Enhancement
Aluminum 7175 Sheet derives its strength from precipitation hardening (age hardening) — a process that refines the microstructure to improve strength and toughness.
Typical Heat Treatment Process
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Solution Heat Treatment
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Heated to ~470°C to dissolve alloying elements and form a homogeneous solid solution.
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Quenching
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Rapid cooling in water to trap the dissolved elements within the aluminum matrix.
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Artificial Aging (T6 or T7351 Condition)
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Controlled heating at 120–160°C allows the precipitation of MgZn₂ particles, which strengthen the alloy.
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The most widely used aerospace tempers are T6 (for maximum strength) and T7351 (for improved stress-corrosion resistance and toughness).
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7175-T6: Provides maximum yield and tensile strength.
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7175-T7351: Offers a balance between strength and stress corrosion resistance, ideal for aircraft structures.
This heat treatment allows the material to achieve consistent high strength while maintaining structural stability under long-term service conditions.
Comparison: 7175 vs 7075 Aluminum Alloy
| Property | Aluminum 7175 | Aluminum 7075 |
|---|---|---|
| Tensile Strength | 510–570 MPa | 480–540 MPa |
| Yield Strength | 440–500 MPa | 410–480 MPa |
| Fracture Toughness | Higher | Moderate |
| Stress Corrosion Resistance | Excellent | Good |
| Fatigue Life | Excellent | Very Good |
| Typical Temper | T7351 | T651 |
| Applications | Aerospace structural parts, landing gear | General aircraft fittings, tools |
While 7075 aluminum remains a popular aerospace-grade alloy, 7175 provides enhanced toughness and better resistance to stress corrosion cracking, making it the preferred choice for critical aircraft load-bearing components.
Corrosion Resistance and Surface Protection
Aircraft Grade Aluminum 7175 Sheet offers excellent resistance to atmospheric corrosion, particularly when exposed to moist environments and aviation fuels. The alloy forms a protective oxide layer that prevents further oxidation and extends service life.
To enhance corrosion resistance, additional surface treatments are often applied, such as:
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Anodizing: Creates a durable oxide coating for long-term protection.
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Cladding: Applying a thin layer of pure aluminum (Alclad 7175) to improve corrosion resistance without affecting strength.
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Chromate Conversion Coating: Provides an extra layer of electrochemical protection.
This ensures that 7175 aluminum sheets perform exceptionally well in marine, coastal, and aerospace conditions where humidity and temperature fluctuations are constant.
Applications of Aircraft Grade Aluminum 7175 Sheet
Thanks to its combination of high strength, lightweight properties, and corrosion resistance, Aluminum 7175 Sheet is used extensively across high-performance industries.
1. Aerospace Industry
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Aircraft wing spars, fuselage frames, and landing gear components
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Engine mounts and aircraft brackets requiring both strength and fatigue resistance
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Military aircraft structures where durability under stress is critical
2. Defense and Military Equipment
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Armored vehicles, missile components, and aerospace-grade fasteners
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Lightweight structural frames that demand impact resistance and toughness
3. Automotive and Transportation
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High-performance vehicle frames and suspension systems
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Components designed to reduce vehicle mass while maintaining safety and rigidity
4. Industrial and Sporting Applications
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Pressure vessels, machinery plates, and marine equipment
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Sports equipment such as high-performance bicycles and climbing gear
Every application benefits from the alloy’s exceptional combination of mechanical strength, dimensional stability, and lightweight efficiency.
Key Advantages of Aluminum 7175 Sheet
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High Strength-to-Weight Ratio – Superior load-bearing capacity with minimal weight.
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Excellent Fatigue and Corrosion Resistance – Designed for long-term durability.
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Outstanding Machinability and Formability – Ideal for precision aerospace parts.
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Excellent Fracture Toughness – Resistant to crack growth under stress.
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Heat Treatable for Custom Performance – T6 or T7351 conditions for tailored mechanical properties.
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Reliable Surface Finish – Anodizing and cladding options for enhanced corrosion protection.
These features make Aircraft Grade Aluminum 7175 Sheet the benchmark for high-strength, lightweight engineering solutions.
Why Choose SASAALUMINUM for 7175 Aluminum Sheet
At SASAALUMINUM, we specialize in the production and global supply of premium-grade aircraft aluminum materials, including 7175 aluminum sheets, plates, and extrusions. Our products are manufactured using advanced melting, rolling, and heat treatment technologies, ensuring precise mechanical consistency and superior flatness control.
Each sheet undergoes rigorous quality inspections, including ultrasonic testing, tensile testing, and corrosion analysis, to meet aerospace standards such as AMS 4048, ASTM B209, and MIL-DTL-46027.
SASAALUMINUM provides customized solutions for aerospace manufacturers, defense contractors, and engineering firms seeking lightweight materials that offer uncompromised strength, reliability, and corrosion resistance.
With our advanced processing capabilities and commitment to excellence, SASAALUMINUM continues to be a trusted global supplier for aircraft-grade aluminum alloys that meet the most demanding technical requirements.
Conclusion
The Aircraft Grade Aluminum 7175 Sheet stands as a symbol of innovation in aerospace metallurgy — combining exceptional strength, fatigue resistance, and lightweight efficiency in one high-performance alloy. Its superior strength-to-weight ratio, heat-treatable microstructure, and corrosion protection make it a material of choice for next-generation aircraft and defense systems.
By reducing weight while maintaining unmatched mechanical reliability, Aluminum 7175 helps engineers design safer, faster, and more efficient aircraft.
At SASAALUMINUM, we take pride in supplying 7175 aluminum sheets that meet the highest international aerospace standards, providing precision, quality, and long-term reliability for your most demanding applications.
Post time: Oct-31-2025