The properties and capabilities of aluminum are relevant for manufacturing applications in the world. Creating aluminum alloys by mixing with other metals makes the metal even more versatile. Depending on the alloying component added to aluminum, the characteristics of the alloy can vary significantly.
Among the most popular alloys of aluminum are aluminum 7075 and aluminum 6061. Are you wondering which of the two is more suitable for your upcoming project?
Some industrial plant clients often ask questions about the selection of 7075 aluminum and 6061 aluminum for their project. FONNOV ALUMINIUM now introduces the comparison of the 7075 and 6061 that customers often mention, hoping to help your industrial design for production. We discuss the two alloys, focusing on the main properties, differences between the alloys, chemical composition, and mechanical properties. We also explain why using aluminum extrusions from FONNOV ALUMINIUM is worthwhile.
If you were to compile the strongest and most versatile aluminum alloys, aluminum 6061 would make the list. Among the heat-treatable alloys, aluminum 6061 is one of the most dynamic and affordable options.
With magnesium and silicon as the main elements, this alloy is not only heat-treatable but also easy to anodize. You can also harden it after the forming process.
Aluminum 6061 is a common feature in construction and architectural projects. Specific applications of the alloy include bridge parts, electronic components, structural moldings, and piping. These applications suit the alloy for its high strength-to-weight ratio, corrosion resistance, and surface quality.
6061 aluminum alloy has several popular tempers as the table below shows:
| Temper | Description |
|---|---|
| 6061-T4 | Heat-treated and aged naturally |
| 6061-T5 | Cooled and aged artificially |
A Review of Aluminum 7075
Aluminum 7075 is popular for its high fatigue strength. The main alloying element in this alloy is zinc, which gives 7075 aluminum strength which is rare in other alloys.
The alloy has fair corrosion resistance and machinability, but its workability and welding capability are poor. It is also sometimes expensive in particular projects. A point worth noting is that it is possible to enhance the strength and hardness of 7075 aluminum through heat treatment, also called tempering.
7075 aluminum alloy has several popular tempers as the table below shows:
| Temper | Description |
|---|---|
| 7075-T6 | Solution heat-treated followed by artificial aging
Temper -T6511 is for products that have been stretched for stress relief |
| 7075-T73 | Solution heat-treated
Stabilized/ over-aged |
Comparing Aluminum 7075 and Aluminum 6061
Significant strength is the most popular feature of 7075 aluminum. Despite the fact that the alloy is difficult to weld and form, it has fair capability for corrosion resistance and machinability.
6061 aluminum is also strong, plus it has good machinability, corrosion resistance, and capability for welding. Unlike 7075 aluminum, this alloy is also easy to form.
Next is a detailed comparison of several characteristics of the two aluminum alloys.
The Chemical Composition of 6061 vs. 7075 Aluminum
You can deduce the chemical difference between 6061 aluminum and 7075 aluminum from the number designation. While 7075 aluminum belongs to the 7XXX series, 6061 aluminum is from the 6XXX series.
Even without a datasheet, it can be determined that 7075 aluminum contains more zinc percentage and 6061 aluminum contains more silicon percentage. Focusing on the ranges of the two aluminum alloys suggests that 7075 aluminum contains more copper and magnesium percentages.
Find below a table showing the specific chemical composition of both aluminum alloys:
| ALUMINIUM ALLOY | Si | Fe | Cu | Mn | Mg | Cr | Zn | Ti | Zr | Others | AL |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 7075 | 0.4 | 0.5 | 1.2-2.0 | 0.3 | 2.1-2.9 | 0.18-0.28 | 5.1-6.1 | 0.2 | —— | 0.15 | reminder |
| 6061 | 0.4-0.8 | 0.7 | 0.15-0.4 | 0.15 | 0.8-1.2 | 0.04-0.35 | 0.25 | 0.15 | —— | 0.15 | reminder |
✣All compositions are in percent.
The Mechanical Properties of 6061 vs. 7075 Aluminum
Some important parameters in this regard are strength, thermal conductivity, electrical resistivity, and elasticity. Others are temperature resistance, material hardness, and corrosion resistance.
The strength of aluminum alloys can be further divided into yield strength, shear strength, and tensile strength.
The yield strength refers to the capability of a material to withstand impact and pressure before deforming. 7075 aluminum is a better performer in this aspect. For instance, the yield strength of T6 temper 7075 can be as high as 480 MPa. 6061 is lower at 276MPa, but this is still a decent level.
The shear strength and tensile strength of 7075 T6 aluminum are also markedly higher than the corresponding figures for 6061-T6 aluminum.
Considering the differences in heat treatment and chemical composition, 6061 and 7075 aluminum are bound to have different thermal conductivities. For your project where heat dissipation is a primary consideration, you might want to pick 6061 aluminum – its thermal conductivity is higher than that of 7075 aluminum.
As you would expect, there is a similar relationship concerning electrical resistivity. While the two aluminum alloys conduct electricity well, electrical resistivity is lower in 6061 aluminum than in 7075 aluminum.
Both aluminum alloys have excellent elasticity and material hardness, but 7075 aluminum has an edge in the capability to resist deformation or cracking amid pressure.
The results are different when it comes to corrosion resistance. Because of the higher copper (sensitive to the environment) content, 7075 aluminum alloy is more prone to corrosion than 6061 aluminum alloy.
| Alloy | Tensile Strength (MPa) | Yield Strength (MPa) | Hardness HBW |
|---|---|---|---|
| 6061-T6 | 260 | 240 | 95 |
| 7075-T6 | 540 | 470 | 150 |
✣The tested value is Min.
7075 Aluminum and 6061 Aluminum Extrusions and Tempers
These alloys are hard, but they can still undergo extrusion. This is through the usual extrusion process comprising the following steps:
- Heating the billet
- Pre-extrusion
- Extrusion
- Cooling
- Aging
- Finishing
Both 7075 and 6061 aluminum are commonly extruded. They are subjected to temperature changes and heat treatment to achieve different tempers. Once subjected to tempering, the mechanical properties of the alloys can vary greatly depending on the specifics of the process.
For 6061 aluminum, the common T tempers designations are as indicated in the table below:
| Temper | Description |
|---|---|
| 6061-T4 | Heat-treated and aged naturally |
| 6061-T5 | Cooled and aged artificially |
| 6061-T6 | Heat-treated
Aged artificially Very common in a wide range of applications |
7075 aluminum is available in several tempers, including the following:
| Temper | Description |
|---|---|
| 7075-T6 | Solution heat-treated followed by artificial aging
Temper -T6511 is for products that have been stretched for stress relief |
| 7075-T73 | Solution heat-treated
Stabilized/ over-aged |
Each of the tempers for 6061 aluminum and 7075 aluminum has unique characteristics. For instance, 7075-T6 is the lightest and most durable of the alloys. It is also usually very expensive. You wouldn’t expect to find this temper outside the aviation and aircraft applications.
Industrial processes usually use 6061-T6 aluminum due to its low weight, durability, and affordability.
Applications of 6061 Aluminum Extrusions
What comes out is that 6061 aluminum has applications in diverse industries due to its affordability, strength-to-weight ratio, and corrosion resistance. From the manufacture of food containers to the design of bicycle frames, 6061 aluminum extrusions have limitless areas of use.
In the automotive industry, these extrusions are used in making important components. These include engines, brakes, and suspensions. The alloy is attractive for these applications due to its strength and lightweight nature. Low weight is a popular characteristic for car bodies, where a combination of low weight and strength is necessary.
Aluminum 6061 is equally popular in the making of aircraft components. Again, this preference is because the alloy offers corrosion resistance and a high strength-to-weight ratio.
Applications of 7075 Aluminum Extrusions
The most popular area of application for 7075 aluminum, like for the rest of the 7000 series alloys, is in the wider area of transport.
7075 aluminum extrusions work excellently in the aerospace industry, where the high strength-to-weight ratio of the alloy comes in handy. The fuselage frames, landing gear parts, and spars of aircraft are typically made from this tough aluminum alloy. The lightness of the alloy enhances fuel economy and the general performance of the aircraft.
7075 aluminum is prominent in vehicle manufacture for the same reasons. Despite the tough operating conditions of the engine, the alloy performs perfectly in connecting rods, pistons, and other components.
Many high-performance parts are also made from the 7075 aluminum alloy. These include bicycle frames and golfing equipment.
Why Buy 6061 and 7075 Aluminum extrusions from FONNOV ALUMINIUM?
With the many tempers of aluminum extrusions, finding the best option for a project can be daunting. Only a thorough understanding of the temper designations and characteristics can help. FONNOV ALUMINIUM is ready to help you pick the most appropriate aluminum extrusion.
We supply high-quality aluminum extrusions coupled with CNC machining and fabrication services. With a focus on producing high-quality extruded aluminum profiles and aluminum products, we are the best partner for your 6061 and 7075 aluminum needs.
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Unmatched Experience
You can rely on the experience and expertise the company has amassed ever since it started operations back in 2014. We can customize the aluminum extrusions to suit your applications in diverse industries.
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Adherence to standards and customer requirements
FONNOV ALUMINIUM clients can rest assured that we have subjected the aluminum extrusions to special principles. The company is continuously seeking to improve the quality standard.
We strictly adhere to the GB/T5237-2008, GB/T6892-2015, and GB/T3191-2019 standards for architectural aluminum extrusion, engineering uses, and aluminum extrusion rods and bars respectively. To further ensure the best quality of 6061 and 7075 aluminum extrusions, our aluminum billets must meet the National Standard GB/T3190-2008.
Our familiarity with international standards such as the European Standard BS EN755 and American Standard ASTM B221 for aluminum extrusion profiles means that our international clients are equally catered for.