• June 21, 2024
  • Shatou, Changan, Dongguan, CN
6061 and 7075 aluminum

6061 vs. 7075 Aluminum: Which Is Right For Your Project?

When choosing a suitable aluminum material, we often face two common choices – 6061 and 7075. Both of these aluminum alloys have excellent strength and corrosion resistance. However, they differ in some ways, so choosing the best option for your project depends on specific requirements.

The purpose of this article is to select the appropriate aluminum alloy for your project by comparing the properties of the two materials in detail.

Chemical composition

The chemical composition of 6061 and 7075 aluminum alloys is slightly different. The table below details the chemical composition of 6061 aluminum and 7075 aluminum.

Chemical element6061 aluminum7075 aluminum
Aluminum (Al)97.9% Al90.0% Al
Magnesium (Mg)1.0% Mg2.5% Mg
Silicon (Si)0.6% Si
Zinc (Zn)5.6% Zn
Copper (Cu)0.28% Cu1.6% Cu
Chromium (Cr)0.2% Cr0.23% Cr

It should be noted that different manufacturers and different manufacturing requirements may have slight differences, and the specific chemical composition can be determined according to the data provided by the manufacturer.

Mechanical properties

6061 aluminum and 7075 aluminum have different mechanical properties, the table below contains a complete breakdown of the mechanical properties of 6061 aluminum and 7075 aluminum.

Mechanical behavior6061 aluminum7075 aluminum
Tensile strength280-310 MPa572-624 MPa
Yield strength240-276 MPa503-550 MPa
Elongation8-12%11-13%
Hardness95-110 HB150-190 HB

Overall, 7075 aluminum alloy is stronger and more durable than 6061 aluminum alloy, but its machinability and weldability are relatively poor. When selecting a suitable aluminum alloy material, it is necessary to comprehensively consider the mechanical properties, machinability and cost of the material according to the specific application requirements.

Manufacturing Considerations

The following are considerations to consider during the manufacturing process:

1. Heat treatment: 6061 aluminum is usually heat treated with T6 to improve its strength and hardness. 7075 aluminum is often used in T6 heat treatment or T73 heat treatment to obtain the best strength and hardness properties.

2. Machining: Due to the higher strength of 7075 aluminum, greater cutting force needs to be used during machining. Additionally, using high-speed drilling and milling tools, along with proper tool materials and lubricants, can help reduce cutting forces and increase tool life.

3. Corrosion protection: Since 6061 aluminum has good corrosion resistance, conventional corrosion protection measures can be used in the manufacturing process. While 7075 aluminum is susceptible to stress corrosion and pitting corrosion, more stringent corrosion protection measures are required, such as the use of appropriate coatings, surface treatments and rust inhibitors.

4. Welding: 6061 aluminum has good welding performance, and conventional welding methods can be used, such as argon arc welding and arc welding. While 7075 aluminum is not suitable for conventional welding, commonly used welding methods include electron beam welding and laser welding.

In short, in the manufacturing process, it is necessary to select appropriate heat treatment, machining, corrosion protection and welding methods according to the different characteristics and uses of 6061 aluminum and 7075 aluminum to ensure that products that meet the requirements are manufactured.

Application field

6061 aluminum alloy is a general-purpose alloy with good processability, weldability, assembly and corrosion resistance. It is suitable for the manufacture of structural parts and components with medium strength requirements, such as construction products, electrical products, pipes, bicycle frames, furniture and automotive parts.

7075 aluminum alloy is a high-strength alloy with high tensile strength and wear resistance, and its strength even exceeds that of many general steels. Therefore, 7075 aluminum alloy is often used in areas that need to withstand heavy loads and high stress, such as aircraft wings and fuselages, missile parts, gears, shafts, worm gears, regulating valves and fuse parts.

Conclusion

If your project requires high strength and hardness, and corrosion resistance is not a primary concern, then 7075 aluminum alloy may be a better fit for your project. And if your project does not require high strength and hardness, but requires good weldability and processability, then 6061 aluminum alloy may be more suitable for your project.

FAQs

1. Which aluminum reacts better to anodizing?

7075 aluminum has a better anodizing reaction than 6061 aluminum. This is because the zinc and copper components in the 7075 aluminum alloy can increase the effect of anodizing. The addition of zinc and copper makes the anodized layer of 7075 aluminum alloy more uniform, dense and wear-resistant, with better corrosion resistance and surface hardness. In contrast, the anodic oxidation reaction of 6061 aluminum alloy is relatively weak.

2. Which is easier to machine, 6061 or 7075 aluminum?

7075 aluminum is easier to machine. This is because 7075 aluminum is relatively softer and has higher processing performance. On the other hand, 6061 aluminum is harder and may require higher machining forces and more skilled operations to machine. So in general, 7075 aluminum is more suitable for processing operations.

3. Can they be formed and welded?

Both 6061 and 7075 aluminum alloys can be formed and welded.

For welding, both 6061 and 7075 aluminum alloys can be welded by common welding methods such as bolt welding, TIG (tungsten arc welding) and MIG (metal inert gas welding). However, due to the high hardness and strength of the 7075 aluminum alloy, higher welding techniques and controls are required to avoid cracks and welding defects.

4. Can you process them?

Yes, we can process them, please provide pictures or samples, we will quote you within 12 hours.

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