The ability to manipulate the functionalization of Ni coating is of great importance in improving the corrosion resistance of Mg alloy for many industrial applications.
In addition to barrier function of the MSNs, the loaded inorganic CI, NaF, can be released when the corrosive medium penetrates the pinholes and diffuses to the corrosion sites, leading to the reaction with Mg ions to form a protective film, MgF2, at the corrosion sites.
The large surface area and pore volume of the MSNs are useful for accommodating and releasing CIs on demand. This approach is first demonstrated in terms of using F-loaded MSNs to construct a totally metallic matrix coating with self-healing functionality for preventing Mg alloy from corrosion.
"In comparison with the healable organic coatings on Mg alloy in previous studies, the metallic Ni coating in the present study has many advantages, including microhardness, antiwear property, etc," the authors conclude their report. "Moreover, as shown by the results, the newly designed [email protected] Ni coating has self-healing characteristics and exhibits significant enhancement in corrosion inhibition over the Ni coating without [email protected]"