Active self-healing coating for galvanically coupled multi-material assemblies

• Self-healing coating based on synergistic mixture of nanocontainers is proposed.
• “Smart” nanocontainers with different inhibitors are incorporated in coatings.
• Active corrosion protection for galvanically coupled AA6061 and CFRP is achieved.

A new “self-healing” coating concept for active corrosion protection on galvanically coupled multi-material structures is reported in the present work. The novel approach is based on the combination of two types of nanocontainers with two different inhibitors in the same coating system. The nanocontainers confer a triggered release of both inhibitors which act in a synergistic way when an aluminum alloy is galvanically coupled with carbon fiber reinforced plastic. The layered double hydroxide and bentonite were used as functional nanocarriers for 1,2,3-benzotriazole and Ce3 + inhibitors respectively. Scanning vibrating electrode technique has been applied for the monitoring of galvanic corrosion activities and kinetics of self-healing processes in confined defects. The effective inhibition of electrochemical activity in the defects on coated galvanically coupled aluminum alloy with carbon fiber reinforced plastic was demonstrated for the first time.