Electrochemical pitting and pepassivation on icosahedral Al-Cu-Fe,and a comparison with crystalline phases

摘要

We report the electrochemical potentials at which localized pitting and repassivation occur on icosahedral Al-Cu-Fe,and on a series of related alloys and elemental metals.The electrochemcistry occurs in a buffered NaCl solution,pH 8.4. Under these conditiosns,pitting and repassivation appear to be controlled mainly be the chaemical composition of the alloy,although the quasicrystalline phase displays an anomalous resistance to repassivation.Corrosion of this phase proceeds by dissolution of Al and Fe,leaving behind pits which are Cu-enriched.