▎ 摘 要
Effect of graphene oxide on the corrosion behavior of electrodeposited Cu-Cr coatings on mild steel substrate was studied and the results were correlated with the texture of the coatings using electron backscattered diffraction. The graphene oxide (GO) prepared using modified Hummer's method was added in five different concentrations (50, 100, 150, 200, 250 mg/L, labelled as GO1, GO2, GO3, GO4, GO5 respectively) by dispersing the prepared GO in the aqueous electrolyte bath. The coatings obtained were found to be compact and without any cracks. The corrosion behavior was studied using potentiodynamic polarization and electrochemical impedance spectroscopy. It was found that with the addition of GO, the corrosion resistance increased significantly compared to the pristine CuCr until the 150 mg/L of GO addition and thereafter it again started to decrease. The corrosion current density obtained for pristine CuCr, CuCr-GO1, CuCr-GO2, CuCr-GO3, CuCr-GO4, CuCr-GO5 was 9.2, 7, 5.4, 4.6, 8.3, and 10.7 mu A/cm(2) respectively. GO3 was found to have the lowest i(corr) which corresponds to highest corrosion resistance. There was a 50 pct reduction in the value of i(corr) by the addition of 150 mg/L of graphene oxide (GO3) compared to pristine CuCr coating. Electron backscattered diffraction analysis revealed a high fraction of low angle grain boundaries (LAGB's), a preferred texture along low energy (111) and (311) planes in case of CuCr-GO3 compared to high energy (101) planes for pristine CuCr. The fraction of LAGB's for pristine CuCr, CuCr-GO3, CuCr-GO5 were found to be 0.21, 0.36, and 0.28, respectively.