Mechanical, tribological and anti-corrosive properties of polyaniline/graphene coated Mg-9Li-7Al-1Sn and Mg-9Li-5Al-3Sn-1Zn alloys

The mechanical, tribological and corrosion protection offered to Mg-9Li-7Al-1Sn and Mg-9Li-5Al-3Sn-1Zn alloys by the epoxy coating containing polyaniline/graphene (PANI/Gr) pigments is undertaken in the current work. PANI/Gr containing coatings were observed to be strongly adherent with a higher scratch hardness (H-s) and plowing hardness (H-p), i.e. H-s of 0.43 GPa, and H-p of 0.61 GPa, respectively when compared to that of neat epoxy coating (H-s of 0.17 GPa, and H-p of 0.40 GPa, respectively). Due to their higher H-s and H-p values, PANI/Gr based coatings displayed an enhanced wear resistance (Wear volume, W-v =4.53 x 10(-3) m(3)) than that of neat epoxy coating (W-v = 5.15 x 10(-3) m(3)). The corrosion protection efficiency in corrosive environment of 3.5 wt% NaCl solution was obtained to be >99% for PANI/Gr containing coatings when compared to that of neat epoxy coating. The charge-transfer resistance (R-ct) of the PANI/Gr containing coatings were estimated to be >10(6) Omega cm(2), which indicates their highly protective nature when compared to that of neat epoxy coating (R-ct similar to 10(5) Omega cm(2)). Hence, PANI/Gr containing coatings can be potentially used for wear resistance and corrosion protection applications in marine environments. (C) 2019 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.