Grade 7075 is the most common of the 7000 series grades. It is an extremely high strength alloy; the strongest of all commercial grades of aluminium. In fact, grade 7075 aluminium is stronger than many types of mild steel.
First off is that the tensile strength of 7075-T6 is nearly double that of 6061-T6. The shear strength of 7075-T6 is roughly 1.5 times that of 6061-T6. The former is substantially harder as well.
Because 6061 aluminum has a higher thermal conductivity than 7075 aluminum, it can be a better choice for certain applications. Of the heat-treatable alloys, 6061 aluminum plate is one of the more versatile and is commonly used for its corrosion resistance and high toughness.
7075 Aluminum
7075 is notable for its high strength-to-weight ratio and improved strength over 6061. Because of this, 7075 is largely used in aerospace, marine and transportation industries. Any industry where high strength and light weight properties are critical, this alloy is preferred.
Strength. Stainless steel is heavier and stronger than aluminum. In fact, aluminum is around 1/3 the weight of steel. Even though stainless steel is stronger, aluminum has a much better strength to weight ratio than stainless steel.
7068 aluminium alloy is one of the strongest commercially available aluminium alloys, with a tensile strength comparable to that of some steels. This material, also known as an aircraft alloy, is heat treatable.
The main alloy ingredients of zinc and copper make 7075 one of the highest strength aluminium alloys available. 7075 in the T6 temper is stronger than most mild steels. 7075 is considered to have good machinability, good corrosion resistance but is not good for welding.
7075 tech sheet T6 temper 7075 has an ultimate tensile strength of 74,000 – 78,000 psi (510 – 538 MPa) and yield strength of at least 63,000 – 69,000 psi (434-476 MPa).
Comparing 2024 and 6061 Yield Strength
The yield strength of 2024 aluminum is greater than 6061 aluminum (324 MPa > 276 MPa). For this reason, 2024 is commonly used for aircraft aluminum applications.
Depending on the heat treatment process, these products can have different material hardness grades. The Brinell scale is the standard measurement system for qualifying material hardness – Aluminum 6061 typically has a Brinell hardness value of 95, while Aluminum 6063 sports a 73.
Aluminum 7075-T6
With a relatively light density of 2.81g/cm3 and an ultimate tensile strength of 83 ksi, 7075 aluminum is one of the strongest and lightest alloys of aluminum available. The T6, of course, means it underwent thermal treatment. Machine gears and aircraft fittings use this alloy.
It depends on the alloy, but 7075-T6 aluminum has nearly double the strength-to-weight of grade 2 titanium. Titanium uses nearly 4 times the embodied carbon (CO2 emitted during the manufacture, transport and construction of materials), and more than 3 times the embodied energy of aluminum.
6061 is one of the strongest aluminum alloys. It is considered the least expensive and most versatile of the heat treatable alloys.
Generally speaking, 7075 is more expensive than 6061 due to its higher strength-to-weight ratio and lighter weight.
7075 aluminum alloy has a higher yield strength than 6061 aluminum. This is due to its chemical composition. Therefore, it withstands more impact and more without deformation than 6061.
7075 Aluminum alloy
Because 7075 has >1% Cu, it is more affected by caustic environments and does not share the high corrosion resistance which other aluminum alloys have. This is a necessary disadvantage, as the high copper content helps make this alloy exceptionally strong.
In short, 6061 T6 is a highly popular type of aluminum because of its versatility, strength, and forming characteristics. It's ideal for projects that require a light, yet strong material.
Bending these tempered alloys is not impossible, but it is very difficult and will most likely require large bend radii to avoid cracking on the outside of the bend. If you're not careful, you can completely fracture the bend line.
6061 is highly weldable, for example using tungsten inert gas welding (TIG) or metal inert gas welding (MIG). Typically, after welding, the properties near the weld are those of 6061-0, a loss of strength of around 80%. The material can be re-heat-treated to restore -T4 or -T6 temper for the whole piece.
7075 wrought aluminum grades have a maximum tensile strength of greater than 572 MPa with a density of 2.8 g/cm3. 304-grade stainless steel, on the other hand, has a tensile strength of 621 MPa and a density of 8 g/cm3. So 7075 aluminum has 90 % of the strength of 304 stainless steel and ~ 1/3 of the weight.
The most important benefit of 7075 aluminum is its high strength. While it does not have the same level of corrosion resistance or weldability that other common alloys due, its resistance to stress and strain makes it highly useful in aerospace applications where it allows for weight savings over steel.
What Makes Welding 2024 and 7075 Challenging? Aluminum alloys of 2024 and 7075 can become susceptible to stress corrosion cracking after welding. This phenomenon is particularly dangerous because it is not detectable immediately after welding. The cracking usually develops later when the component is in service.
It is technically possible to weld 7075 aluminum. If a welder applies heat, they can join two pieces together. But the result isn't what a layperson might think. When a welder applies high heat to 7075 aluminum, it creates microcracks as it cools.
Aluminum 6063 is somewhat more ideal for the extrusion process, but 6061 is typically stronger. So, if strength is the determining factor for an application, 6061 may be the optimal choice between the two.
7075 is considered to have fair/average machinability. It machines very similarly to aluminium 6082T6. This guide will take you through the main attributes, common applications, notes for designers and suitable finishing and treatments, as well as UK stock sizes and property tables.