The effects of homogenization annealing on the microstructure

hardness and corrosion resistance of as-cast 7050 aluminum alloy were analyzed by optical microscope

scanning electron microscope

X-ray diffraction

differential scanning calorimeter

hardness test

polarization curve test and intergranular corrosion test. The experimental results indicate that the coarse η phases is gradually transformed into S phases and continuously dissolved in the Al matrix during homogenization annealing at 465 ℃. However

the Al

7

Cu

2

Fe phases are dissolved in the Al matrix. The over-burnt phenomenon is observed after homogenization annealing at 465 ℃ for 36 h.With the holding time increasing

the hardness of the alloy is also gradually increased to be stable

where the corrosion potential is firstly increased and then decreased

the corrosion current and intergranular corrosion depth are firstly decreased and then increased. With homogenization treatment at 465 ℃ for 24 h

the alloy exhibits desirable corrosion resistance.