Surface treatment of Cf/Al composites with immersion in aqueous solution containing Ce ions for corrosion barrier

Abstract

In this study, Ce-rich coating is investigated as corrosion inhibitor of carbon fibers reinforcement aluminum matrix (Cf/Al) composites. The coatings are obtained by immersion in aqueous solution containing Ce(NO 3 ) 3 onto composite surface, whereas the Ce-rich coating process produces a coating with highly heterogeneous nature of the surface, but micro-cracked layer with ''dry-mud'' morphology. The coatings were composed of Ce-rich nano-particles, Ce-rich particles with a sphere-like morphology, which are agglomerated particles with diameter 4 $ 8 nm and piled up for this coating. TEM observation for Ce conversion coating of the corresponding ring-like SAED patterns could not be matched to any of the previously reported structures of cerium compounds. Results of high-resolution XPS spectra of Ce3d obtained for Ce conversion coating show that the Ce3d spectra has several components with binding energies characteristic of Ce 3þ and Ce 4þ . The Ce-rich coating process produces effective corrosion protecting of Cf/Al composites, which is verified by electrochemical measurement results. The R t values of coated sample are higher than those of uncoated sample, this confirms the better corrosion resistance of coating obtained after immersion treatment for Cf/Al composites.