What is the difference between 6082 and 7075 aluminum?

The main differences between 6082 and 7075 aluminum are the following properties:

Alloy Series and Chemical Composition

Mechanical behavior

Processing Precautions

application

Alloy series and chemical composition

Perhaps the most obvious difference between the 6082 and 7075 is found by looking at their numbered designations. It belongs to the 6XXX series of aluminum alloy grades, and 7075 belongs to the 7XXX series. Knowing the general properties of the 6XXX and 7XXX series aluminum alloys, without even delving into their respective material data sheets, one can see that there are several important differences in chemical composition.

The 6XXX series are aluminum grades alloyed with magnesium and silicon. The 7XXX series are aluminum grades alloyed with zinc and magnesium. Therefore, it can be determined that it has a higher silicon content, whereas 7075 has a higher zinc content. When looking at the exact range of chemical compositions between the two alloys, 7075 also has more copper added to its chemical composition.

Mechanical behavior

Both 6082 and 7075 are heat treatable, so in order to directly compare the two, they must be evaluated under the same type of heat treatment. When looking at the two alloys in the -T6 temper (i.e., solution heat treated and then artificially aged), several distinct differences can be observed. The first is that 7075-T6 has almost twice the tensile strength of 6082-T6. 7075-T6 has approximately 1.5 times the shear strength of 6082-T6. The 6082-T6 is also quite soft compared to the 7075-T6.

Manufacturing Notes

Generally speaking, it is easier to manufacture than 7075. Its lower strength, lower hardness and slightly higher ductility are responsible for this. Its lower hardness makes it easier to turn, mill, drill and otherwise machine than 7075. Lower tensile strength means 6082-T6 is easier to form than 7075.

While both materials can be joined by welding, brazing or adhesives, it is weldable, whereas 7075 is generally considered non-weldable. Although it is considered weldable, care must be taken to select the proper weld filler metal. Post weld heat treatment and aging may be required to return the weld area to the original "-T" marking. 7075 is extremely susceptible to cracking after welding.

Application of 7075 Aluminum

There is a lot of application overlap between the 6082 and 7075s aluminum alloys. As mentioned, both are structural grade aluminum. Both are used in bicycle parts, aerospace components and building structures.

However, they are used differently in these areas. For example, in the aerospace industry, 7075s may be more likely to be used as gears or rods, and may be more likely to be implemented in areas where higher ductility is required. For bike parts, some riders prefer the higher strength offered by 7075 aluminum alloy. 7075 is more likely to be used in molds and industrial tools than 6082. Since it is easier to form than 7075, it is more commonly used for tanks and other shapes with rounded contours.