AC impedance analysis was carried out on the surface oxide films formed on aluminum by three surface treatments:
1) electropolishing, 2) chemical polishing, and 3) immersion in H₃PO₄/CrO₃ solution. The pretreated specimens were anodized in a neutral phosphate solution to examine the effects of the initial surface films on the subsequent formation of anodic oxide.
It was found that the equivalent circuits for the surface films were all expressed as parallel combinations of resistance (R_ox) and capacitance (C_ox) components. The value of Rox decreased in the order of pretreatments (1)>(3)>(2); the order was reversed for C_ox. Dielectric constant and specific resistivity of the films were estimated and the relationship between the electrical properties and the chemical composition is discussed.
The Cl^- ions incorporated in the surface film formed by treatment 1) led to the formation of anodic oxide films with a relatively large number of defects. The inner layer of the anodic oxide films was composed of pure Al₂O₃, and it was thinner for films with pretreatment 3) than those with 1) and 2). This is explained in terms of the effects of pre-existing films on ion transport during subsequent anodizing.

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The oxygen evolution reaction (OER) on nickel alloy films (nickel, electroless Ni-B and electroless Ni-P) in 1mol dm^-3 KOH solution was investigated by electrochemical techniques, specifically an impedance method using the fast Fourier transform (FFT). The OER on electroless Ni-B electrode showed the highest electrocatalytic activity in the high overpotential region, while that on electroless Ni-P electrode gave the lowest activity. The capacitance component (Cp) due to adsorbed intermediate had a strong correlation with the OER catalytic order, with electroless Ni-B electrode giving higher Cp values in all overpotential regions.

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A theory for the decay of the wet shear strength of adhesion has been proposed by formalizing the quantitative relation between wet shear strength of adhesion and moisture content. Theoretical values for the retention of wet shear strength of adhesion over time coincided with the experimental plottiugs. It has been clarified that the diffusion coefficient of water is larger at the interface than in the adhesives, and that moisture absorption is determined by the diffusion of water at the interface.

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Samples in which nickel was electrodeposited on copper plate from Ni (CF₃COO)₂-halide-MeOH baths at 1.5A/dm² at 30°C until thickness reached about 50μm, were prepared. Measurements were conducted to determine the polarization curves and corrosion weights of the nickel in 1.5N acid solutions (HCl, H₂SO₄ and HNO₃) and the nickel surfaces were observed before and after acid exposure. It was found that the behavior for acids was affected by both cations and anions of the halide in the bath from which the nickel was electrodeposited.

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