A new approach to enhancing interlaminar strength and galvanic corrosion resistance of CFRP/Mg laminates

In the present research, AZ31 magnesium alloy was treated by electrochemical methods in Na2SiO3-KOH-KF and KOH-KF electrolytes, and the morphological features of films formed on magnesium alloy were assessed. Besides, the effect of Mg surface features on interlaminar failure load, failure mode and galvanic corrosion resistance of CFRP/Mg laminates were investigated. The results show that removal of silicate in the Na2SiO3-KOH-KF electrolyte can cause the transition of conversion film from ceramic-like oxide film to pitted oxide film. The pitted oxide film can effectively enhance the peel strength of CFRP/Mg laminates compared with the ceramic-like oxide film, and an average enhancement of 6.5 times was observed. The pitted oxide film on magnesium can provide an excellent protection against the galvanic corrosion in CFRP/Mg laminates as the ceramic-like oxide film.