A novel coating system with self-reparable slippery surface and active corrosion inhibition for reliable protection of Mg alloy

Inspirations from nature have led to extensive developments of biomimetic nonwetting surfaces and intelligent self-healing technologies toward corrosion protection of metals. Integration of both intriguing features contributes to achieving diversified protections. In this work, we engineered a novel anticorrosion system composed of a plasma electrolytic oxidation (PEO) film, a layered double hydroxide (LDH) film and a lubricant-infused slippery surface on Mg alloy. The PEO film grown in situ on Mg alloy could render a moderate corrosion barrier, and the sandwiched LDH film integrated ternary roles involving loading corrosion inhibitor, anchoring lubricant and sealing PEO defects. The outermost slippery surface exhibited durable repellence against water and also self-reparable capability to surface damage. The robust and self-reparable film barrier coupled with active corrosion inhibition endowed this system with superb anticorrosion performance. The dynamic self-healing processes associated with barrier regeneration and corrosion inhibition were substantiated at microscale using scanning Kelvin probe and scanning vibrating electrode technique, respectively. It is expected that this research would shed light on the design of multifunctional anticorrosion systems for Mg alloy.