An aluminum silicate modified Ni-Al LDHs film to improve the corrosion resistance of AZ31 Mg alloy

摘要

Improving the corrosion resistance of Mg alloys is essential for broadening its application. In this paper, the aluminum silicate-modified Ni-Al layered double hydroxides (LDHs) were synthesized by co-precipitation, and then the aluminum silicate-modified Ni-Al LDHs film was fabricated on the surface of AZ31 Mg alloy to improve the anti-corrosion property via a facile in-situ growth method. The results showed that the aluminum silicate modified Ni-Al LDHs film could effectively improve the corrosion resistance of AZ31 Mg alloy and could maintain for a long time. Comparing to that of the bare AZ31 Mg alloy, the corrosion current density of the one with the aluminum silicate modified Ni-Al LDHs film was decreased by 2 orders of magnitude. It was due to the blocking effect of the aluminum silicate modified on the Ni-Al LDHs and the adsorption of Cl- by the LDHs film, delaying the corrosion of the Mg alloys. This work not only broadens the modification method of LDHs but also provides a new strategy for the corrosion protection of Mg alloys. (C) 2019 Published by Elsevier B.V.