Potential of chitosan -treated Pr(III) conversion coating as an environmentally corrosion mitigator for corrosion of AZ۳۱B Mg alloy

The presence of new additive compound like chitosan in the green praseodymium conversion coating (Pr(III)CC) converted it to a potent source of powerful sustainable soft compound for AZ۳۱B magnesium alloy corrosion mitigation. The EIS analyses, SEM and salt spray testing(SST) observations have been employed for studying the formation procedures, structure, and characteristics of the pr(III) conversion coating (Pr(III)CC) /۰.۱%chitosan-treated pr(III) conversion coating (Pr(III)CH۰.۱CC) formed in the baths. The SEM demonstrated that the adsorption of chitosan solution components on the Mg alloy surface gave rise to a smooth surface morphology with few damaged areas. the lowest conversion coating failure in SST was for the sample with ۰.۱% chitosan solution. On the basis of polarization curves it was found that the conversion coating post-treatment showed a mixed effect in corrosion inhibition with a minor cathodic prevalence. EIS data showed that the highest Impedance and charge-transfer resistance and the lowest corrosion rate is for the sample coated Pr(III)CH۰.۱CC after ۵h immersion.

کلیدواژه ها:

chitosan solution ، praseodymium based conversion coating ، EIS ، SEM ، salt spray