LAUSR

Abstract An environment-friendly cerium-based conversion coating (CeCC) was prepared by alternating electric field assisted treatment for the modification of magnesium-aluminum (Mg-Al) hydrotalcite (HT) film on AZ91D Mg alloy. The influence of cerium nitrate (Ce(NO 3 ) 3 ) concentration was evaluated in terms of morphology, composition, and corrosion resistance. The results showed that deposition behavior (including deposition amount and sealing effect) of CeCC was controlled by Ce(NO 3 ) 3 concentration. The HT film treated with 10 g/L Ce(NO 3 ) 3 was better sealed; the HT film immersed in 30 g/L Ce(NO 3 ) 3 displayed larger deposition amount of CeCC. With the increase in concentration from 5 to 40 g/L, the corrosion resistance exhibited a waving trend. The treated HT film with better sealing effect or larger deposition amount revealed superior corrosion resistance.