Electrochemical corrosion behaviour of rolled dual phase Mg-8Li-graphene composite

Abstract

In this research, the effect of interrupted rolling on electrochemical corrosion behaviour of Mg-8Li-xGr composite is investigated. Graphene reinforced composite was developed by using stir casting route and rolled with different reductions in thickness of 50, 75 and 90%. Investigation on potentiodynamic polarization of rolled composite depicts that increase in reduction percentage increases the corrosion rate of the developed composite. Electrochemical impedance studies reveal that composite reduced at 50% thickness exhibits higher charge transfer resistance of 80 Ωcm2. Nyquist plot depicts occurrence of inductance loop that reveals occurrence of oxide layer breakage. Addition of graphene up to 0.4 wt% increase the corrosion resistance and further addition exhibits adverse effect in corrosion behaviour due to the galvanic effects. The occurrence of pitting corrosion is evidenced from corrosion surface morphology.