1. Core Definition & Standard Classification

7075 aluminum alloy is a heat-treatable ultra-high-strength alloy, formulated with zinc as the primary alloying element, complemented by magnesium and copper to achieve its remarkable strength. It adheres to stringent global standards, reflecting its critical role in safety-sensitive applications:

• Core Standards: ASTM B209 (primary standard for aluminum plate/sheet), AMS 4045 (aerospace-grade T6 temper), AMS 4046 (T73 temper), EN 573-3 (European standard), GB/T 3880 (Chinese standard)

• Grade Positioning: The "workhorse" of ultra-high-strength aluminum alloys—offering 2–3 times the strength of 6061, with a strength-to-weight ratio exceeding many structural steels

• Key Temper States: Heat treatment is critical to unlocking its performance; T6 (peak strength) and T73 (stress corrosion cracking resistance) are the most widely used:

• O: Annealed, fully soft state (rarely used for 7075 due to low strength)

• T6: Solution heat treated + artificial aging (peak strength, ~80% of industrial applications)

• T651: T6 + stress-relieved stretching (0.5–3% elongation) for flatness and stability (ideal for large plates)

• T73: Solution heat treated + stabilized aging (superior stress corrosion cracking resistance, critical for aerospace)

• T76: T73 variant with slightly higher strength and moderate SCC resistance

2. Chemical Composition & Core Alloy Functions

7075 aluminum plate’s ultra-high strength stems from its precise alloy chemistry, where synergistic interactions between elements create dense strengthening precipitates (MgZn₂, Al₂CuMg). Below is its standardized chemical composition (mass fraction, %):

Core Alloy Advantage

The combination of Zn, Mg, and Cu enables 7075 to achieve ultra-high strength through heat treatment: during solution annealing and aging, fine, uniformly distributed precipitates pin dislocations in the aluminum matrix, resulting in strength levels comparable to low-carbon steel—while maintaining 30% of steel’s weight.

3. Key Technical Properties

3.1 Mechanical Properties (Typical Values for 6–50mm Plate, Key Tempers)

7075’s mechanical performance is unmatched among commercial aluminum alloys, with tempers tailored to balance strength and durability:

3.2 Physical Properties

7075 maintains stable physical properties across its operational temperature range (-200℃ to 120℃):

• Density: 2.81 g/cm³ (1/3 of steel; 4% denser than 6061 due to alloy additions)

• Melting Point: 475–635℃ (varies by temper and composition)

• Thermal Conductivity: 130 W/m·K (lower than 6061; still efficient for heat dissipation)

• Electrical Conductivity: 33% IACS (adequate for non-critical electrical applications)

• Coefficient of Thermal Expansion: 23.1×10⁻⁶/℃ (slightly lower than 6061; good dimensional stability)

3.3 Corrosion Resistance & Durability

• General Corrosion Resistance: Moderate; prone to intergranular corrosion (IGC) and stress corrosion cracking (SCC) in T6 temper due to Cu-rich precipitates at grain boundaries

• SCC Resistance: T73 temper offers excellent SCC resistance (superior to T6) via stabilized precipitates; T6 requires surface protection for harsh environments

• Protective Measures: Anodizing, chromate conversion coating, or paint is mandatory for outdoor, marine, or humid applications; anodized 7075 achieves 95%+ integrity after 300 hours of salt spray testing

• Limitation: Not recommended for long-term exposure to chloride-rich environments (e.g., seawater) without advanced corrosion protection

4. Product Forms & Dimensional Range

7075 aluminum plate is supplied in specialized configurations to meet high-performance requirements, with strict dimensional controls:

4.1 Core Product Forms

• Hot-Rolled Plate: Thickness ≥6mm (primary form for structural applications)

• Cold-Rolled Sheet: Thickness ≤6mm (for precision components and decorative parts)

• Key Variants: Flat plate, precision-cut blanks, forged plate (for extreme load applications), and clad plate (7075 core with 6061 cladding for enhanced corrosion resistance)

4.2 Standard Dimensional Range

• Thickness: 0.8mm (sheet) to 250mm (heavy plate); customized up to 400mm for defense/military use

• Width: 1000mm–2600mm (standard); customized up to 3000mm for large aerospace components

• Length: 2000mm–6000mm (standard); cut-to-length available (minimum 500mm for precision blanks)

• Dimensional Tolerance: Thickness ±0.04mm (precision sheet) to ±0.4mm (heavy plate); width/length ±0.8mm (standard)

4.3 Surface Treatment Options

To address corrosion limitations and enhance performance, 7075 supports targeted surface treatments:

• Anodizing: Hard anodization (25–50μm thickness) for wear and corrosion resistance; available in natural, black, or custom colors

• Chromate Conversion Coating: Thin, adherent layer (0.5–2μm) for improved paint adhesion and corrosion protection

• Powder Coating: Durable decorative finish; ideal for outdoor structural parts requiring aesthetics

• Cladding: 6061 or 7072 cladding (0.5–2mm thickness) to provide a corrosion-resistant barrier without compromising core strength

5. Production Process & Quality Control

7075 aluminum plate requires precision manufacturing and rigorous quality control to ensure consistency in ultra-high-strength applications:

1. Raw Material Smelting: High-purity aluminum ingots + alloy elements (Zn, Mg, Cu, Cr) smelted in vacuum induction furnaces; degassing to remove hydrogen (≤0.15ml/100g) and impurities

2. Ingot Casting: Direct chill (DC) casting to form uniform ingots; homogenization annealing (460–480℃ for 12–24 hours) to eliminate segregation and dissolve coarse precipitates

3. Hot Rolling: Ingots heated to 420–450℃; hot-rolled to target thickness using thermo-mechanical control processing (TMCP) to refine grain structure

4. Cold Rolling: For thin sheets (≤6mm); precision rolling to achieve tight tolerances and smooth surface finish (Ra ≤0.8μm)

5. Heat Treatment: Critical for strength optimization:

• T6 Temper: Solution heat treatment (475–485℃ for 2–4 hours) + water quenching (≤20℃/s cooling rate) + artificial aging (120–125℃ for 24 hours)

• T73 Temper: Solution heat treatment + water quenching + two-step aging (100℃ for 10 hours + 150℃ for 8 hours) to stabilize precipitates

• T651 Temper: T6 process + stress relief stretching to eliminate internal stress and ensure flatness

6. Surface Finishing: Cleaning, degreasing, and optional anodizing/cladding

7. Quality Inspection & Testing:

• Chemical Testing: Spectrometric analysis (per ASTM E1086) to verify alloy composition compliance

• Mechanical Testing: Tensile, bend, hardness, and fatigue tests for each production batch

• Non-Destructive Testing (NDT): Ultrasonic testing (UT, per ASTM A609) for internal defects; eddy current testing (ECT) for surface cracks; radiography (RT) for critical aerospace components

• Corrosion Testing: Intergranular corrosion (IGC) testing (per ASTM G110) and SCC testing (per ASTM G44) for T73 temper

8. Certifications: All products come with EN 10204 3.2 certification; aerospace-grade products meet AMS 4045/4046 and AS9100/ISO 9001 standards; military-grade products comply with MIL-DTL-46027

6. Core Applications

7075 aluminum plate’s ultra-high strength and strength-to-weight ratio make it the material of choice for high-stress, safety-critical applications:

6.1 Aerospace & Aviation

• Aircraft structural components (wing spars, fuselage frames, landing gear struts), helicopter rotor hubs, satellite brackets, and rocket motor casings

• Rationale: Strength comparable to steel + 70% weight reduction; T73 temper used for components exposed to humid environments (e.g., wing leading edges)

6.2 Defense & Military

• Armor plates, missile components, military vehicle hulls, and tactical equipment (rifle barrels, tripod mounts)

• Rationale: Ultra-high strength (T6 temper) + impact resistance; withstands ballistic threats while maintaining mobility

6.3 Precision Engineering & Tooling

• High-precision mold plates, CNC machine tool components, and jigs/fixtures

• Rationale: Dimensional stability + high hardness; resists deformation under heavy machining loads

6.4 Transportation (High-End)

• Performance automotive parts (roll cages, suspension components), racing boat hulls, and high-speed rail bogie frames

• Rationale: Lightweight strength improves speed, fuel efficiency, and maneuverability

6.5 Sports & Recreation

• High-end sports equipment (golf club shafts, bicycle frames, climbing gear)

• Rationale: Strength-to-weight ratio enhances performance; durability withstands extreme use

7. Cost & Pricing Considerations

7075 aluminum plate’s premium performance comes with a higher price tag than standard aluminum alloys, driven by alloy complexity, processing requirements, and quality controls (2025 Q4 data):

7.1 Global Price Ranges

7.2 Key Pricing Drivers

7.2.1 Temper & Processing Complexity

• T6/T651 (Peak Strength): Baseline price (100%); most cost-effective for high-strength needs

• T73 (SCC Resistance): 15–25% premium over T6; justified for safety-critical aerospace applications

• T76 (Balanced Strength/SCC): 10–15% premium over T6; middle ground for non-aerospace high-stress parts

• Clad Plate (Corrosion-Resistant): 20–30% premium; cladding adds material and processing costs

7.2.2 Thickness & Form Factor

• Thin Sheets (0.8–3mm): 25–35% higher than medium plates; precision rolling and quenching costs

• Medium Plates (3–50mm): Baseline price; optimized for mass production of structural parts

• Heavy Plates (50–250mm): 15–20% premium; custom heat treatment and NDT requirements

• Precision Blanks: 30–40% premium; CNC cutting and tight dimensional tolerances (±0.03mm)

7.2.3 Quality Grade & Certification

• Commercial Grade (ASTM B209): Baseline price; suitable for non-critical high-strength applications

• Aerospace Grade (AMS 4045/4046): 40–60% premium; strict composition control + batch traceability

• Military Grade (MIL-DTL-46027): 50–70% premium; ballistic testing + extreme environment validation

• Third-Party Certification (SGS/BV/Nadcap): 5–10% additional cost; mandatory for aerospace/defense

7.2.4 Order Quantity & Supplier Type

7.3 Price Comparison with Other High-Strength Alloys

7.4 Cost Optimization Strategies

• Bulk Purchasing: Orders ≥5 tons unlock manufacturer-direct pricing, reducing costs by 18–30% vs specialty distributors

• Standard Tempers: Choose T6 over T73 if SCC resistance is not critical (saves 15–25%)

• Avoid Over-Specification: Use commercial grade (ASTM B209) for non-aerospace applications (saves 40–60% vs aerospace grade)

• Domestic Sourcing: Chinese-manufactured 7075 offers 20–30% cost savings vs Western suppliers, with comparable quality for commercial applications

• Long-Term Contracts: Annual supply agreements lock in prices and provide 5–8% additional discounts, mitigating zinc/magnesium price volatility

8. Temper Selection Guide & Key Considerations

Choosing the right temper balances strength, durability, and cost for 7075 aluminum plate:

9. Supply Chain & Value-Added Services

• Minimum Order Quantity (MOQ): Specialty distributors: 50kg; manufacturers: 1 ton (aerospace grade: 5 tons)

• Delivery Lead Time: Stock commercial grade: 7–14 days; custom aerospace grade: 25–45 days

• Packaging: Aerospace-grade packaging (vacuum-sealed plastic + wooden crates) to prevent corrosion; heavy plates secured with steel strips

• Value-Added Services: Precision CNC cutting, drilling, bending, anodizing, and cladding; additional 10–25% cost

• Global Supply Hubs: Core production bases in China (Shanghai, Guangdong), USA (California, Ohio), and Europe (Germany, UK); loading ports cover major aerospace logistics hubs

10. Conclusion

7075 aluminum plate stands as the gold standard for ultra-high-strength aluminum applications, delivering unmatched strength-to-weight ratio, durability, and reliability in critical industries. Its unique alloy chemistry and heat-treatable properties make it the material of choice for aerospace, defense, and precision engineering—where performance and safety cannot be compromised. While it carries a premium price tag compared to standard aluminum alloys, its ability to replace heavier steel while maintaining strength justifies the investment for weight-sensitive, high-stress applications.

Pricing flexibility allows buyers to optimize costs through strategic temper selection, bulk purchasing, and avoiding over-specification. When paired with appropriate surface treatments (e.g., anodizing, cladding), 7075 overcomes its corrosion limitations, extending its utility to outdoor and marine environments. Backed by stringent quality controls, global certifications, and a mature supply chain, 7075 aluminum plate remains the top choice for engineers and buyers seeking ultra-high strength without sacrificing lightweight performance.