7075 Hliník

7075 Aluminum is one of the world’s most widely used and highly regarded aluminum alloys.

Known for its exceptional strength-to-weight ratio and excellent mechanical properties, hliník 7075 is a favorite in the aerospace and sports equipment industries.

In this comprehensive guide, we will delve into everything you need to know about 7075 hliník, from its composition and properties to its applications and fabrication techniques.

1. Co je 7075 Hliník?

7075 aluminum is part of the 7xxx series, characterized by zinc as the primary alloying element.

It is a heat-treatable alloy, designed to deliver high strength and toughness, making it suitable for applications that demand durability and precision.

While its primary use is in the aerospace industry, its versatility has allowed it to gain popularity in other high-performance sectors as well.

2. 7075 Aluminum Properties

Chemické vlastnosti

The chemical composition of 7075 aluminum includes a combination of elements that provide strength, tvrdost, a odolnost proti korozi.

Živel	Typical Percentage (%)	Role
Hliník (Al)	Váhy	Base element, providing lightweight and formability.
Zinek (Zn)	5.1–6.1	Primary strengthening element, enhances hardness and tensile strength.
Hořčík (Mg)	2.1–2.9	Improves corrosion resistance and increases strength.
Měď (Cu)	1.2–2.0	Increases hardness and machinability but reduces corrosion resistance.
Chromium (Cr)	0.18–0.28	Improves resistance to stress-corrosion cracking.
Křemík (A)	Max 0.4	Controls grain structure, minor strengthening effect.
Železo (Fe)	Max 0.5	Impurities with minor effects on strength.

The precise balance of these elements creates a high-performance alloy suited for demanding applications.

Fyzikální vlastnosti

The physical attributes of aluminum 7075 contribute to its widespread use in the aerospace and automotive industries.

Vlastnictví	Hodnota	Popis
Hustota	2.81 g/cm³	Lightweight compared to steel, making it ideal for weight-sensitive applications.
Bod tání	477–635 °C	Allows for high-temperature applications and easy fabrication.
Tepelná vodivost	130 W/m · k	Mírný, suitable for heat-dissipating parts.
Elektrická vodivost	36% IACS	Decent electrical conductor for structural materials.
Koeficient tepelné roztažnosti	23.6 µm/m·°C	Maintains dimensional stability under varying temperatures.

These properties make aluminum 7075 a reliable material for parts that require a combination of lightweight, rigidity, and heat management.

3. Common Temper Grades of 7075 Hliník

Each temper grade of 7075 aluminum provides a unique balance of mechanical properties. Here’s a detailed breakdown:

7075-O (Žíhané)

• Proces: annealed condition
  No heat treatment is applied. The alloy is fully annealed to maximize formability and ease of machining.
• Mechanické vlastnosti:

• • Ultimate Tensile Strength: ~220 MPa
  • Výnosová síla: ~105 MPa
  • Prodloužení: ~17–18%

• Characteristics:

• • Softest form of 7075 hliník, making it highly workable for forming operations.
  • Ideal for applications where post-machining heat treatment is planned.

• Aplikace: Used in situations requiring extensive forming or welding, such as complex aerospace components.

7075-T6 (Solution Heat Treated and Aged)

• Proces: the solution is heat-treated and artificially aged
  The alloy is heated to a high temperature, held at that temperature for some time to dissolve the alloying elements into the matrix, a pak se rychle ochladilo (uhasit) to lock these elements in solution.
  It is then artificially aged at a lower temperature to precipitate the alloying elements and increase strength.

• Mechanické vlastnosti:

• • Ultimate Tensile Strength: ~572–580 MPa
  • Výnosová síla: ~503–540 MPa
  • Prodloužení: ~11–13%

• Characteristics:

• • High strength-to-weight ratio, excellent for load-bearing components.
  • Reduced ductility compared to 7075-O.

• Aplikace: Common in aerospace, automobilový průmysl, and sporting goods industries for parts like wing spars and bicycle frames.

7075-T651 (Solution Heat Treated, Cold Worked, and Aged)

• Proces: solution heat-treated, stretched, and artificially aged
  Similar to T6, but the alloy is stretched after quenching to relieve internal stresses and improve straightness.
• Mechanické vlastnosti:

• • Ultimate Tensile Strength: ~572–580 MPa
  • Výnosová síla: ~503–540 MPa
  • Prodloužení: ~11–13%

• Characteristics:

• • Similar to T6, but with improved dimensional stability due to stress relief.
  • Slightly better machinability compared to T6.

• Aplikace: Preferred for precision machining, such as high-performance tools, díly letectví, a formy.

7075-T73 (Solution Heat Treated, Overaged)

• Proces: Solution heat-treated, then overaged to improve corrosion resistance.
• Mechanické vlastnosti:

• • Ultimate Tensile Strength: ~503–540 MPa
  • Výnosová síla: ~435–475 MPa
  • Prodloužení: ~13–15%

• Characteristics:

• • Slightly lower strength than T6 but much better resistance to stress corrosion cracking.
  • Suitable for applications exposed to corrosive environments.

• Aplikace: Used in marine equipment, aerospace applications requiring corrosion resistance, a strukturální komponenty.

7075-T7351 (Solution Heat Treated, Cold Worked, and Overaged)

• Proces: Solution heat-treated, stretched, and overaged:
  After solution heat treatment and stretching, the alloy is overaged at a higher temperature to reduce residual stress and improve fracture toughness.
• Mechanické vlastnosti:

• • Ultimate Tensile Strength: ~503–540 MPa
  • Výnosová síla: ~435–475 MPa
  • Prodloužení: ~13–15%

• Characteristics:

• • Combines the benefits of stress relief and corrosion resistance.
  • Less prone to warping and dimensional instability.

• Aplikace: Ideal for precision aerospace parts, military applications, and high-performance machinery.

Summary Table of Mechanical Properties

Temper Grade	Ultimate Tensile Strength (MPA)	Výnosová síla (MPA)	Prodloužení (% in 50mm)	Klíčové vlastnosti
7075-O	~ 220	~105	~17–18	Highly ductile and formable.
7075-T6	~572–580	~503–540	~11–13	Maximum strength, low ductility.
7075-T651	~572–580	~503–540	~11–13	Stress-relieved, excellent machinability.
7075-T73	~503–540	~435–475	~13–15	Enhanced corrosion resistance.
7075-T7351	~503–540	~435–475	~13–15	Corrosion-resistant and stress-relieved.

Effects of Heat Treatment Stages

1. Solution Heat Treatment (SHT):
   During this stage, the alloy is heated to dissolve its alloying elements into a solid solution. Rapid cooling, or quenching, “locks in” the alloying elements, setting the stage for hardening.
2. Zhášení:
   Rapid cooling from the solution treatment temperature creates a supersaturated solid solution. This step is critical for achieving high strength but introduces residual stress in the material.
3. Aging (Natural or Artificial):
   Aging allows the alloying elements to precipitate, enhancing the alloy’s strength and hardness. Artificial aging, performed at elevated temperatures, is faster and more controlled.

Key Factors Influenced by Tempering

1. Síla a tvrdost:

• • T6 and T651 Tempers deliver the highest strength due to optimized precipitation of alloying elements like zinc and magnesium.
  • T73 Temper sacrifices some strength for enhanced corrosion resistance, suitable for environments prone to stress-corrosion cracking.

2. Odolnost proti korozi:

• • T6 temper is moderately corrosion-resistant but can be prone to stress-corrosion cracking.
  • T73 temper is specifically designed to improve corrosion resistance, particularly in marine or chemical applications.

3. Machinability and Stress-Relief:

• • T651 temper minimizes internal stresses, allowing for high-precision machining without the risk of warping or deformation.
  • T73 temper may be less machinable due to its softer surface but offers greater dimensional stability in corrosive conditions.

4. Toughness and Ductility:

• • T6 temper provides adequate toughness for structural applications.
  • T73 temper offers higher ductility, making it more resistant to cracking under impact or extreme loading.

4. Výhody 7075 Hliník

7075 aluminum stands out as one of the most versatile and high-performance alloys available, offering a range of advantages that make it a popular choice across industries:

Exceptional Strength-to-Weight Ratio

• 7075 aluminum is renowned for its impressive strength-to-weight ratio, making it a prime choice for applications requiring lightweight yet durable materials.
  Například, it boasts an ultimate tensile strength of up to 572 MPA (83,000 psi) in the T6 temper, surpassing many steels while remaining significantly lighter.

Excellent Fatigue Resistance

• This alloy is highly resistant to fatigue, making it ideal for components subjected to repetitive stress.
  This property is especially valued in the aerospace and automotive industries, where reliability under cyclic loading is critical.

Superior Machinability

• 7075 aluminum’s machinability enables the production of complex and precise parts with ease.
  It is often rated as one of the best aluminum alloys for CNC machining, zkrácení doby výroby a nákladů.

Tepelná léčitelnost

• The ability to tailor mechanical properties through tempering and heat treatments like T6 and T651 increases its versatility.
  This flexibility allows engineers to customize the alloy for specific performance requirements.

Odolnost proti korozi

• While not as corrosion-resistant as 6061, 7075 aluminum offers moderate resistance to environmental factors.
  Anodizing or other surface treatments can further enhance its durability against corrosion.

5. Processing of 7075 Hliník

7075 aluminum’s unique properties make it suitable for various fabrication methods, including forming, obrábění, a povrchové ošetření.

Obrábění:

• 7075 aluminum is excellent for machining processes like CNC frézování, otáčení, a vrtání. Its high machinability allows for precise and efficient fabrication.

Formování:

• 7075 aluminum can be formed into various shapes, but it may require annealing to improve formability. This process helps in achieving the desired shape without compromising the material’s properties.

Tepelné zpracování

• 7075 is heat-treatable, enabling enhanced strength and tailored mechanical properties through processes like solution heat treatment and aging. Tempers such as T6 and T651 offer maximum strength, while T73 provides improved corrosion resistance.

Svařování

• Welding is not generally recommended due to the risk of cracking. Friction stir welding is a viable alternative for high-quality joints.

6. Different Finishes on 7075 Hliník

Mill Finish:

• The natural finish as it comes from the mill, is suitable for applications where appearance is not critical.

Eloxování:

• Provides a protective oxide layer that enhances corrosion resistance and can be colored for aesthetic purposes. Anodizing improves the material’s durability and appearance.

Leštění:

• Achieves a smooth, reflective surface, often used for decorative or high-precision applications. Polishing can enhance the visual appeal and reduce surface roughness.

Malování:

• Coated with paint or other protective coatings to enhance appearance and protect against corrosion.
  Painting is a common method for improving the material’s aesthetics and longevity.

Chemical Conversion Coatings:

• Treatments like chromate conversion coating (Alodine) improve corrosion resistance and adhesion for subsequent coatings.
  These coatings are essential for enhancing the material’s performance in harsh environments.

7. Where to Use 7075 Hliník

Aerospace:

• 7075 aluminum is widely used in aircraft structures, wings, and fuselage components due to its high strength and lightweight properties.

Automobilový průmysl:

• High-performance vehicle parts, such as suspension components and chassis, benefit from the strength and durability of 7075 hliník.

Sportovní vybavení:

• 7075 aluminum is used in bicycle frames, golf club shafts, and ski bindings, where high strength and light weight are crucial.

Marine:

• Boat hulls and deck fittings benefit from the material’s corrosion resistance and strength, making it ideal for marine applications.

Industrial:

• Structural components, machinery parts, and tools often use 7075 aluminum for its high strength and reliability.

8. Comparison of 7075 Aluminum with Other Grades

Each aluminum grade has its unique set of properties and is best suited for specific applications. 7075 aluminum stands out for its high strength and lightweight.

Však, other grades like 6061, a 2024 offer different advantages in terms of formability, svařovatelnost, a nákladová efektivita, making them suitable for a broader range of applications.

Vlastnictví	7075	6061	2024
Pevnost	Higher	Mírný	Vysoký
Odolnost proti korozi	Mírný	Vynikající	Mírný
Machinability	Vynikající	Dobrý	Mírný
Svařovatelnost	Limited	Vynikající	Limited
Náklady	Vysoký	Mírný	Vysoký
Aplikace	Aerospace, military	General engineering	Aerospace, automobilový průmysl

9. Forms Aluminum 7075 Alloy Exists

7075 aluminum is available in a wide range of forms, providing flexibility for various manufacturing processes and applications.

Below are the most common forms in which this alloy exists and their typical uses:

Form	Popis	Typické aplikace
Flats	Thin, flat pieces ideal for structural components.	Aerospace panels, automotive reinforcements.
Kulaté tyče	Solid cylindrical shapes for machining.	Shafts, kolíky, upevňovací prvky, and aerospace fittings.
Plates	Thick flat sheets used for heavy-duty parts.	Tooling plates, structural components.
Sheets	Thin, wide surfaces for lightweight structures.	Aircraft skin, Panely, and cladding.
Strips	Narrow sheets for precision cutting.	Electrical components, decorative trim.
Round Tubes	Hollow cylindrical shapes.	Bicycle frames, fluid transport systems.
Rectangular Tubes	Hollow rectangular cross-sections.	Structural frames, Automobilové komponenty.
Hollow Bars	Thick-walled tubes for heavy-duty applications.	Hydraulic cylinders, Aerospace komponenty.
Square Bars	Solid square profiles for diverse uses.	Construction parts, brackets, and joints.
Hexagon Bars	Hexagonal shapes for specialized fasteners.	Bolts, nuts, and machine components.
Channels	U-shaped profiles for structural support.	Building frameworks, aerospace ribs.

10. Závěr

7075 aluminum is a remarkable alloy that combines high strength, lehký, and excellent mechanical properties.

Each temper grade offers unique characteristics, allowing engineers and manufacturers to select the most appropriate material for their specific needs.

Whether you are working on aerospace projects, Automobilové komponenty, or high-end sports equipment, 7075 aluminum is a material worth considering.

By understanding its composition, vlastnosti, and fabrication techniques, you can maximize its potential and achieve outstanding results in your projects.

We hope this guide has provided you with valuable insights into the properties of 7075 hliník.

If you have any questions or product processing needs, feel free to reach out to us. Happy fabricating!