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.