Effect of two-stage aging on hardness and electrical conductivity of as-extruded 7075 aAluminum Alloy

The effect of two-stage aging on the microstructure and properties of as-extruded 7075 aluminum alloy was studied by means of hardness, conductivity and microscope. The results show that: in the process of solution and primary aging, with the increase of heat treatment time, the hardness and electrical conductivity of the alloy have little improvement, but there is a strong linear correlation between hardness and electrical conductivity, that is, the change of hardness and electrical conductivity presents the same trend; after two-stage aging treatment, with the extension of aging time, the hardness of the alloy first increases, reaches the peak value, and then decreases gradually, the hardness and conductivity have a strong negative linear correlation; and with the increase of aging temperature and aging time, the hardness of the alloy decreases by 9.6%, while the conductivity increases by 18.6%.