Aluminum alloy materials have high relative strength, excellent strength-to-weight ratio, corrosion resistance, and easy to process, which are very popular. Wide range of applications in construction, aerospace, sports equipment, electrical and automotive industries and other fields. We all know that there are many types of aluminum alloys available, with 6061 and 7075 aluminum being the most popular and common. While the two materials are similar in some ways, there are significant differences. In order to allow customers to choose the most suitable material for the project more efficiently, we will compare the difference between 6061 aluminum and 7075 aluminum in this article.
Before we discuss the difference between 6061 aluminum and 7075 aluminum, let's first understand what 6061 aluminum and 7071 aluminum are.
6061 Aluminum alloy is one of the most commonly used aluminum grades. It has good tensile strength, mechanical properties, and corrosion resistance. In addition, it has excellent formability and ease of manufacture, it is an excellent choice for producing various precision parts in different shapes and many extrusion projects.
6061 aluminum was called “Alloy 61S” when it was originally developed in 1935, is a member of the 6000 series. 6061 aluminum’s main alloying elements are magnesium and silicon. Among them, aluminum accounts for 95.8 to 98.6%, magnesium accounts for 0.8 to 1.2%, silicon accounts for 0.4 to 0.8%, and other trace elements such as copper and chromium.
7075 aluminum was first secretly developed by a Japanese company in 1936 and later introduced by American alloy company in 1943. Its main alloy component is zinc, and the proportion of each component is 5.6% to 6.1% of zinc, 2.1% to 2.5% of magnesium, 1.2% to 1.6% of copper and a small number of other metals such as silicon, manganese, chromium, titanium, iron and so on.
Aluminum 7075 is a member of the 7000 series and is one of the strongest aluminum alloys. It is comparable in strength to many types of steel, but is much less dense and has an excellent strength-to-weight ratio. So it is often an excellent substitute for steel. This property makes Alloy 7075 very popular in the aerospace and defense industry.
It also has excellent properties such as good fatigue resistance and good ductility, and it is widely used in high-stress applications and aircraft structural components.
Of course, 7075 aluminum is not all about its advantages. Because 7075 aluminum has exceptionally high strength, it is not easy to process, form and weld, and its cost is relatively high compared to other aluminum alloys.
6061 and 7075 have similar chemical elements, and both contain magnesium, silicon, copper, iron, zinc, titanium, manganese, and chromium. It's just that the proportions are different.
The main alloy components of 6061 aluminum are silicon and magnesium while the main alloy components of 7075 aluminum alloy are zinc and copper.
Material hardness
Due to 6061 aluminum containing less zinc than 7075, 7075 aluminum is harder than 6061 aluminum. This also makes 7075 aluminum not easy to machine and weld
Corrosion resistance
7075 aluminum has much higher amount of copper than 6061 aluminum. While copper reacts more with the environment and is easier to occur corrosion.The reason why 6061 aluminum alloy is more resistant to corrosion than 7075 is not far-fetched.
Electrical resistivity
Aluminum alloy is a good electrical conductor as it has low electrical resistivity. Compared with 7075 aluminum, 6061 has the lowest electrical resistivity.
Thermal conductivity
6061 aluminum’s thermal conductivity is slightly higher than that of 7075 aluminum.
Temperature resistance
7075 aluminum melting point is 477 – 635°C while 6061 is 582 – 652°C. 7075 aluminum has a slightly lower. Thus, 6061 alloy can withstand higher temperatures
Use 6061 when:
Need to consider the cost
just for decoration
You need to do a lot of machining or welding on the project
They are usually used in the following areas
Building products
Such as subway platforms, stairs, floors, decking, walk away, etc.
Consumer products
such as bicycle frames and components, awnings
Marine supplies
6061 has strong corrosion resistance. When the 6061 aluminum surface has an additional effective coating of powder coating or spray paint, seawater will not have a corrosive effect on the 6061 aluminum. This is why 6061 aluminum is widely used in fishing equipment such as fishing reels, scuba diving equipment, SCUBA water tanks, marine firearms, moorings, dock gangways, yachts, marine fittings, and hardware etc.
6061 aluminum is also used in boat hulls, as it is about one-third the weight of steel, improving fuel efficiency and saving costs.
Public transport industry
Auto parts, modern aircraft parts. Due to its excellent machinability, 6061 aluminum is used in the aircraft industry for welding and joining different parts of aircraft.
Food industry, like canned food and beverage cans
Furniture
Electrical products
Piping
Moldings
Use 7075 when:
No need to consider the cost.
Both high strength and low weight need to be considered.
The parts need to be hard.
The part will be exposed to a lot of heat
Parts will be exposed to a lot of friction and require very good wear resistance.
They are usually used in the following areas
Missile parts, Aircraft components, spacecraft, and other defense applications.
Shows up in other parts subject to high wear, structural materials, and military applications. Like Gears and shafts
Fuse parts
Regulating valves
When choosing aluminum alloy materials, more people will choose 6061 aluminum for their CNC machining parts. Because the 6061 is almost always better than the 7075. A big reason is that 6061 aluminum has lower hardness and tensile strength. Resulting in 6061 aluminum being easier to machine and form than 7075. Even machining 7075 aluminum would cost more. Therefore, if you do not need super hardness and high wear resistance, 6061 aluminum is enough for most of the project