7075 T6511 Aluminum

What is 7075-T6511 aluminum?

As an important member of the 7000 series aluminum alloys, 7075-T6511 aluminum alloy holds an irreplaceable position in modern industry due to its excellent high strength and good machinability.

7075 T6511 Aluminum Standards:

ASTM B221 Standard specification for aluminum alloys in various forms, including extruded shapes.
AMS QQ-A-200/11 High-standard performance requirements for aluminum alloys, suitable for aerospace and military applications.

As a representative of high-strength aluminum alloys, 7076-T6511 aluminum alloy is applied in multiple fields such as aerospace, automobile manufacturing, and military defense due to its excellent mechanical properties, good machinability, and diverse product forms.

7075-T6511 is a specific heat treatment temper, with the following process characteristics:

Definition of T6511 temper: T6511 indicates that the alloy has undergone solution heat treatment, artificial aging, and stress relief during the straightening process.
Pre-stretching process: 7075-T6511 aluminum alloy is obtained by subjecting 7075 aluminum alloy to solution heat treatment and age hardening, followed by pre-stretching with a strain of 0.5%~2%. This process helps improve the material's strength and machinability, while reducing deformation issues during subsequent processing.
Difference from T6510 temper: Compared with the T6510 temper, the T6511 temper allows straightening by stretching during processing, resulting in a flatter and more stable surface.
Performance advantages: The alloy in T6511 temper offers an excellent balance of strength and toughness, along with good dimensional stability and machinability, making it particularly suitable for applications requiring high-precision machining.

7075-T6511 aluminum

Material properties: 7075-T6511 aluminum alloy features high strength, high hardness, high elastic modulus, and moderate corrosion resistance, making it a structural material with excellent overall performance.
Product forms and applications: 7075-T6511 aluminum alloy is supplied in various forms such as bars, plates, tubes, and profiles, and is widely used in aerospace structural components, high-performance automotive parts, military equipment, precision machinery components, and high-end consumer electronics.
Processing technology: The production and processing of 7075-T6511 aluminum alloy involve multiple stages, including smelting and casting, hot working, cold working, heat treatment, and surface treatment.
Performance comparison: Compared with other aluminum alloys such as 6061, 2024, and 7050, 7075-T6511 aluminum alloy stands out in terms of strength and hardness but has certain limitations in corrosion resistance and processing difficulty.
Material selection: 7075-T6511 aluminum alloy is suitable for applications requiring high strength, hardness, and lightweight characteristics, with relatively lower requirements for corrosion resistance and cost.

Material properties of 7075-T6511 aluminum alloy

Composition and structure of 7075-T6511 aluminum alloy

Element	Percentage
Al	90
Cr	0.18 - 0.28
Cu	1.2 - 2
Fe	0.5 max
Mg	2.1 - 2.9
Mn	0.3 max
Si	0.4 max
Ti	0.2 max
Zn	5.1 - 6.1
Zr+Ti	0.25 max

7075-T6511 aluminum alloy is obtained by subjecting 7075 aluminum alloy to solution heat treatment and age hardening, followed by pre-stretching with a strain of 0.5%~2%. This process focuses on enhancing the material's strength and machinability, giving 7075-T6511 aluminum alloy a high specific strength and toughness, as well as good corrosion resistance, making it more suitable for precision machining.

7075 T6511 Aluminum Mechanical Properties

Property	Value
Density g/cm^3	3
Ultimate Tensile Strength KSI	80
Yield Tensile Strength KSI	67
Brinell Hardness 500 kg load	150
Elongation % in 2 in.	8
Melting Point °F	890 - 1180
Electrical Conductivity % IACS	33
Machinability %	70
Shear Strength KSI	48
Rockwell Hardness B Scale	87

Physical Properties of 7075-T6511 Aluminum Alloy

The physical properties of 7075-T6511 aluminum alloy are also worth noting:

Density: Approximately 2.81 g/cm³, much lighter than steel, giving it a significant advantage in applications requiring lightweight materials.
Melting point: The melting range is approximately 475-635°C, requiring precise temperature control during heat treatment.
Coefficient of thermal expansion: The average coefficient of thermal expansion (20-100°C) is about 23.2-23.6 μm/m·K, similar to other aluminum alloys.
Thermal conductivity: About 130 W/m·K, providing good heat transfer performance.
Electrical conductivity: Approximately 33-41% IACS, with electrical resistivity around 0.0515-0.058 Ω·mm²/m, indicating moderate electrical conductivity.

Corrosion Resistance of 7075-T6511 Aluminum Alloy

Corrosion resistance is one of the important characteristics of 7075-T6511 aluminum alloy:

Basic corrosion resistance: Compared with other aluminum alloys (such as 6061 alloy), the corrosion resistance of 7075-T6511 alloy is relatively weaker. This is mainly due to its more complex alloy composition, especially the higher zinc content, which makes it more susceptible to corrosion.
Corrosion resistance after surface treatment: Through proper surface treatments, such as anodizing or other coating processes, the corrosion resistance of 7075-T6511 aluminum alloy can be significantly improved.
Susceptibility to stress corrosion cracking: 7075-T6511 aluminum alloy has a tendency to stress corrosion cracking, so special attention should be paid to stress distribution and environmental factors in design and usage.
Sensitivity to intergranular corrosion: This alloy has a certain sensitivity to intergranular corrosion, especially under specific heat treatment conditions.

Other Characteristics of 7075-T6511 Aluminum Alloy

In addition to the above main characteristics, 7075-T6511 aluminum alloy also has the following features:

Machinability: Offers good machinability, suitable for turning, milling, and other mechanical processing. Its fine grain structure enhances deep drilling performance, improves tool wear resistance, and provides superior thread rolling quality.
Good usability: After precision machining and processing, it offers good structural stability, making it suitable for a wide range of applications.
Weldability: Weldability is relatively poor, usually requiring special welding techniques and materials, such as gas-shielded welding using aluminum-silicon filler wire.
Heat treatment response: This alloy is highly responsive to heat treatment, and its mechanical properties can be significantly improved through appropriate heat treatment processes.

Common Product Forms of 7075-T6511 Aluminum Alloy

Product Form	Description
Aluminum Square Bar	7075-T6511 aluminum square bar is a high-strength, excellent corrosion-resistant aluminum alloy profile commonly used to manufacture parts requiring precise dimensions and outstanding structural strength. Due to its uniform cross-section and easy machinability, it is widely used in aerospace, automotive, and mechanical industries, especially for frames, brackets, and support structures.
Aluminum Round Bar	7075-T6511 aluminum round bar offers an excellent combination of high strength and lightweight properties, making it an ideal choice for manufacturing high-stress mechanical parts and moving components. It is commonly used in aerospace, automotive, and military industries, particularly in parts like shafts, gears, and supports that require high strength and good toughness.
Aluminum Rectangle Bar	7075-T6511 aluminum rectangle bar is known for its outstanding strength, hardness, and corrosion resistance, widely used to manufacture industrial parts that endure significant stress. Its rectangular cross-section makes it suitable for use as framework structures, support components, and strength-critical parts in aerospace and mechanical engineering.
Aluminum Angle	7075-T6511 aluminum angle is a high-strength aluminum alloy profile commonly used for manufacturing frame structures and supports. Its angled cross-section makes it extremely useful in supporting and connecting structures, often found in aerospace, construction, and military equipment, able to withstand very high mechanical stress.
Aluminum Extruded Bar	7075-T6511 aluminum extruded bar features a uniform cross-section and excellent mechanical properties, widely applied in industries with high-strength demands. Its extrusion process allows for the flexible production of various sizes and shapes, making it especially suitable for structural components, frames, and applications requiring additional strength and stability in aerospace, transportation, and other fields.

7075-T6511 Aluminum Rods

Aluminum rods are one of the most common product forms of 7075-T6511 aluminum alloy, including round rods, square rods, and rectangular rods in various types.

7075-T6511 Round Rod

Specifications: Diameter range is usually 3.0–600 mm, with common specifications such as 45–150 mm, 80–200 mm, etc.
Features: Offers an excellent combination of high strength and lightweight properties, making it an ideal choice for manufacturing high-stress mechanical parts and moving components.
Applications: Widely used in aerospace, automotive, and military industries, especially for parts requiring high strength and good toughness such as shafts, gears, and supports.

7075-T6511 Square Rod

Specifications: Cross-sectional dimensions typically range from 4×4 mm to 200×200 mm, and can even reach up to 600×600 mm.
Features: A high-strength, corrosion-resistant aluminum alloy profile with a uniform cross-section and easy machinability.
Applications: Commonly used for manufacturing parts requiring precise dimensions and excellent structural strength, widely applied in aerospace, automotive, and machinery industries.

7075-T6511 Rectangular Rod

Specifications: Cross-sectional dimensions depend on specific requirements, with width and height typically between 10–200 mm.
Features: Excellent strength, hardness, and corrosion resistance. Its rectangular cross-section provides outstanding performance when subjected to stress in specific directions.
Applications: Extensively used in manufacturing high-stress industrial parts, such as frame structures, support components, and critical strength parts in aerospace and mechanical engineering.

7075-T6511 Aluminum Extruded Rods

Extruded aluminum rods are another important form of 7075-T6511 aluminum alloy:

Specifications: Extruded rods come in various cross-sectional shapes, including round, square, rectangular, and special shapes, with diameters or side lengths typically ranging from 10–300 mm.
Features: Uniform cross-section and excellent mechanical properties. The extrusion process allows flexible production of various sizes and shapes.
Applications: Especially suitable for structural components, frames, and applications requiring extra strength and stability in aerospace, transportation, and other industries.

7075-T6511 Aluminum Plates

Specifications: Plate thickness usually ranges from 0.3–550 mm, with width and length determined as needed.
Features: High strength and good flatness stability, with excellent surface quality after special processing.
Applications: Widely used in aerospace structural components, automotive body panels, molds, jigs, and various applications requiring high-strength lightweight materials.

Other Forms of 7075-T6511 Aluminum Products

7075-T6511 Aluminum Angle

Features: Has an angular cross-section, making it highly suitable for supporting and connecting structures.
Applications: Commonly used in aerospace, construction, and military equipment, capable of withstanding very high mechanical stresses.

7075-T6511 Aluminum Tubes

Specifications: Tube diameter and wall thickness are determined based on application requirements. Common types include seamless aluminum tubes and welded aluminum tubes.
Applications: Used for manufacturing structural parts and fluid transmission systems requiring high strength and lightweight properties.

Application Fields of 7075-T6511 Aluminum Alloy

With its excellent performance, 7075-T6511 aluminum alloy is widely used in multiple fields:

Aerospace Field

Aircraft structural components such as wing spars, fuselage frames, and skins
Spacecraft components such as rocket structures and satellite support structures
Missile and weapon system components
Aero-engine parts

Automotive Manufacturing Field

Structural parts and accessories for high-performance automobiles
Racing car frames and chassis components
Automotive suspension and drivetrain components
Lightweight vehicle body structural parts

Military and Defense Field

Armored vehicles and military equipment
Weapon systems and ammunition components
Military aircraft and helicopter components
Bulletproof armor and protective structures

Industrial and Mechanical Field

High-stress mechanical parts and moving components
Molds and jigs, especially for plastic injection and die casting molds
High-precision machinery components
High-strength supports and frames in construction structures

In addition, 7075-T6511 aluminum is also used in consumer electronics, sports equipment, medical devices, marine engineering, special vehicles, and more.

Processing Technology of 7075-T6511 Aluminum Alloy

Smelting and Casting Process

The production of 7075-T6511 aluminum alloy begins with smelting and casting:

Raw material preparation: High-purity aluminum, zinc, magnesium, copper, and other metals are selected as main raw materials to ensure the chemical composition meets standard requirements.
Smelting process: Raw materials are heated in a furnace to 700–750°C for smelting, with appropriate refining agents and modifiers added to remove impurities and improve alloy casting performance.
Casting process: The molten alloy is typically cast into ingots using semi-continuous or continuous casting processes. Cooling rate and casting temperature must be strictly controlled to achieve uniform microstructure and good mechanical properties.
Homogenization treatment: Cast ingots usually undergo homogenization annealing by heating to 450–480°C and holding for a period of time to eliminate casting stress and improve alloy structure uniformity.

Hot Working Process

Ingots after homogenization treatment need to go through a series of hot working processes:

Hot rolling process: Ingots are heated to 400–450°C and hot-rolled through multiple passes to produce plates or coils of the required thickness. Grain refinement and improved mechanical properties are achieved during hot rolling.
Forging process: For parts requiring even higher strength and more uniform structure, forging is used. Heated alloy billets are forged on a press to improve microstructure and mechanical properties through plastic deformation.
Hot extrusion process: For rods, tubes, and profiles, hot extrusion is commonly used. Heated ingots are placed in an extrusion press, and extruded through a die to form the required cross-sectional shape and dimensions. Hot extrusion temperatures typically range from 350–450°C depending on product shape and size.

Cold Working Process

The cold working processes of 7075-T6511 aluminum alloy mainly include:

Cold rolling process: Hot-rolled plates or coils can be further processed by cold rolling to achieve more precise dimensions and better surface quality. Cold rolling is usually done at room temperature, reducing material thickness through multiple passes while increasing strength and hardness.
Cold drawing and cold pulling process: For rod and tube products, cold drawing or cold pulling can be used for fine processing to obtain higher dimensional accuracy and surface finish. Cold working causes work hardening, increasing strength and hardness but reducing toughness.
Machining: 7075-T6511 aluminum alloy has good machinability, suitable for turning, milling, drilling, tapping, and other machining operations. Due to its high hardness, appropriate cutting tool materials and parameters are needed.

Heat Treatment Process

Heat treatment is the key process to improve the performance of 7075-T6511 aluminum alloy:

Solution heat treatment: The alloy is heated to 475–495°C and held for sufficient time to fully dissolve strengthening phases into the aluminum matrix, forming a uniform solid solution.
Quenching: After solution treatment, rapid cooling (quenching) is required, usually by water quenching or air cooling, to retain the supersaturated solid solution formed at high temperature.
Artificial aging: The quenched alloy is heated to 110–130°C and held for 12–24 hours to allow uniform precipitation of strengthening phases from the supersaturated solid solution, thereby improving strength and hardness.
Stress relief: For certain high-precision parts, stress relief may be required, usually by holding at a lower temperature (such as 120–150°C) for a period to eliminate internal stresses generated during processing.

Surface Treatment Process

To improve corrosion resistance and surface quality of 7075-T6511 aluminum alloy, surface treatments are typically performed:

Anodizing — The most common surface treatment for 7075-T6511 aluminum alloy. Through electrolytic oxidation, a dense aluminum oxide film forms on the surface, significantly improving corrosion resistance and wear resistance.
Chemical conversion treatment — Includes chromate conversion and non-chrome conversion methods, forming a thin conversion coating on the surface to enhance corrosion resistance and provide a good base for subsequent coatings.
Painting and coating — For applications requiring higher corrosion resistance and decorative effects, painting or spraying can be used. Common coating materials include acrylic, polyester, and epoxy organic paints, as well as ceramic and metal-ceramic inorganic coatings.
Electrophoretic coating — A process in which organic coatings are deposited on the surface via electrophoresis, forming a uniform, dense coating with excellent corrosion resistance and decorative quality.

Advantages and Limitations of 7075-T6511 Aluminum Alloy

Main Advantages of 7075-T6511 Aluminum Alloy

High strength-to-weight ratio: An extremely high strength-to-weight ratio makes it an ideal choice for lightweight structures.
Excellent mechanical properties: Features high strength, high hardness, and good toughness.
Good machinability: Although processing is challenging, good machining quality can be achieved with appropriate processes and equipment.
Mature production technology: 7075 aluminum alloy has decades of production and application history, with mature technology and stable quality.
Diverse product forms: Available in various product forms to meet different application needs.
Recyclability: Aluminum alloys are 100% recyclable, with recycling energy consumption only about 5% of primary aluminum production.

Main Limitations of 7075-T6511 Aluminum Alloy

Relatively poor corrosion resistance: Compared with alloys like 6061, 7075-T6511 has poorer corrosion resistance and requires surface treatment.
Sensitivity to stress corrosion cracking: Prone to stress corrosion cracking under certain conditions, requiring special attention in design and use.
High machining difficulty: Due to high hardness, special tooling and process parameters are needed, resulting in higher machining costs.
Poor welding performance: Welding tends to cause cracks and deformation, requiring specialized welding technology and equipment.
Higher cost: Due to complex alloy composition and demanding production processes, its cost is significantly higher than common aluminum alloys.
Low-temperature brittleness: May exhibit increased brittleness at extremely low temperatures, limiting its use in some cryogenic environments.

Material Selection Guide

High strength requirement 7075-T6511 and 7050-T7451 aluminum alloys are the best choices, especially for lightweight applications. For extremely high strength needs, high-strength steel or carbon fiber composites can be considered, balancing weight and cost factors.
High corrosion resistance requirement 6061 aluminum alloy is the best choice, offering excellent corrosion resistance and good overall performance. For marine or highly corrosive environments, stainless steel or composites can be considered.
High toughness requirement 2024-T351 aluminum alloy has good toughness and moderate strength, suitable for applications requiring high toughness. For extreme toughness needs, 7050-T7451 aluminum alloy or composites can be considered.
High thermal conductivity requirement 6061 aluminum alloy and pure aluminum have higher thermal conductivity, suitable for applications needing efficient heat dissipation. For extremely high thermal conductivity, copper or copper alloys can be considered.
High electrical conductivity requirement 6061 aluminum alloy and pure aluminum have higher electrical conductivity, suitable for electrical and electronic applications. For extremely high conductivity, copper or silver can be considered.
Lightweight requirement 7075-T6511 and 7050-T7451 aluminum alloys provide lightweight solutions while maintaining high strength. For ultimate lightweight needs, carbon fiber composites or aluminum-lithium alloys can be considered.