Microstructure and Corrosion behavior of wrought AZ80 Mg alloys after the combined processes of ECAP and Hot Rolling

In the current work, wrought AZ80 Mg alloys were subjected to equal channel angular pressing (ECAP) followed by hot rolling (HR). Then, combined effects of ECAP and HR on microstructure and electrochemical corrosion behavior were investigated in 3.5wt.% NaCl solution. The microstructure and corrosion morphology study was made through optical and scanning electron microscope respectively. The results show that the use of hot rolling after ECAP significantly decreases the grain size compared to as-received and ECAP-4 pass processed Mg alloys. In addition, electrochemical impedance spectroscopy and potentiodynamic polarization results have shown that the hot rolling of AZ80 Mg alloy after ECAP exhibited lower corrosion current and higher corrosion resistance is due to fine grain microstructure and continuous and uniform distribution of secondary phases. This was evidently observed during this study.