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The electrodeposition of Fe Ni alloys was performed galvanostatically in the sulfate solutions of pH 1 3 at 40°C and the alloy deposition behavior was compared with that of Zn iron group metal alloys to investigate their codeposition mechanism. The deposition behavior of Fe Ni alloy showed a typical feature of the anomalous codeposition, in which electrochemically less noble Fe deposits preferentially under most plating conditions. The anomalous codeposition behavior in Fe Ni alloy deposition was evidently dependent on the pH buffer capacity of the solutions. This can be explained in terms of the preferential adsorption of FeOH on the deposition sites of more noble Ni due to the extremely smaller dissociation constant of FeOH ＋ than NiOH ＋ in the multi step reduction process of hydrated iron group metal ions. Keywords: electrodeposition, iron nickel alloy, anomalous codeposition, iron group metal

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The effect of equal-channel angular pressing (ECAP) on the pitting corrosion resistance of Al and Al-Mg alloy was investigated by means of polarization curves in solutions containing 300 ppm of Cl À and by surface analysis. The potentials for pitting corrosion of Al and Al-Mg alloy were clearly shifted in the noble direction by the ECAP process, indicating that this process improves resistance to pitting corrosion. SEM observations revealed that pitting corrosion occurred near impurity precipitates and that the size of the impurity precipitated decreased as a result of the ECAP process. The time-dependence of corrosion potential and the polarization resistance determined using the AC impedance technique suggest that the ECAP process increases the rate of formation of Al oxide films. The improvement in pitting corrosion resistance of Al and AlMg alloy by ECAP appears to be attributable to a decrease in the size of impurity precipitates and an increase in the rate of formation of Al oxide films.