Pitting corrosion and repassivation of Al65Cu23Fe12 quasicrystals and corrosion characteristics of quasicrystalline Al65Cu23Fe12 modified by additives

Abstract

The corrosion resistance of quasicrystalline Al65CU23Fe12 is important because of the unusual properties of quasicrystals. The electrochemical pitting in 0.1 M sodium chloride was studied by voltammetry to determine the value of E[Subscript pit] and E[Subscript rp] with comparisons to different phases. Metal composition appeared to be a factor in the final value of E[Subscript pit] and EP[Subscript rp]. Structure did not appear to be the overwhelming factor in the final result. The open circuit corrosion was investigated on the quasicrystalline Al65Cu23Fe12. by Tafel and polarization resistance measurements in 0.5M perchloric acid. The additives changed the electrochemical values of I[Subscript corr], indicating a higher rate of corrosion for sodium chloride. This higher rate was inhibited by the use of other sodium halides. The halide effect was investigated at a variety of pH regions. The results showed no effect from the use of additives. The quasicrystalline Al65Cu23Fe12 was connected to a stainless steel, to determine the effect of their proximity in solution. The results showed the quasicrystal corrodes first with no apparent effect on the stainless steel.