Electrodeposited palladium films were obtained by the use of the direct current and pulsed current electrolysis in ethylenediamine-palladium (II) complex solutions. The effects of electrolysis parameter on the current efficiency, hydrogen content and morphology of palladium deposits were investigated under varying conditions of electrolysis. Direct current electrolysis, increases in current density resulted in a black, dusty deposit reduced current efficiency and higher hydrogen content. The adoption of pulsed current electrolysis made it possible to obtain smooth deposits of fine grain and to lower the hydrogen content markedly. This behavior is thought to be due to the fact that the pulsed current density (I_p) and off-time (T_off) have a considerable affect on the deposits. The fine grain deposits were obtained by inducing a large overpotential as a result of increasing I_p. It would seem that the smooth deposits were due to the occurrence of T_off, which had the effect of depressing the concentration polarization on account of the mass transport of metal ions on electrode surface. In addition, it is thought that the hydrogen is removed from the deposits during T_off.

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The mechanism and the rate-determining step of the carbon deposition reaction on iron in CH₄^- H₂ mixtures at 1273K have been studied. X-ray diffraction and chemical analysis show that filmy carbon has a well developed crystalline character with crystallite height and interlayer spacing, and that iron is included in it. The growth rate of filmy carbon is controlled by the outward diffusion of iron in the film, while the deposition rate of filamentous carbon is determined by the following overall reaction at the gas-iron interface;
CH₄(g)→C(s)+2H₂(g).

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The anodic behavior of Ag electrode, which is strongly associated with high power alkaline batteries, was investigated mainly by the FFT impedance method. Silver dissolution and some complicated oxide formation stages were interpreted by postulating plausible equivalent circuits. The impedance results showed that the silver dissolution reaction could be represented as the Randles circuit, indicating that the reaction was controlled by the diffusion of Ag (I) to the bulk solution. The Cole-Cole plots of the measured impedance distinctly revealed the differences between the formation reactions for Ag₂O and AgO: the Ag₂O reaction showed the resistance and capacitance components typical of dielectric materials, while that for AgO included factors characteristic of conductors.

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The application of electroplated Ni-P alloys as the matrix metal for abrasion -resistant SiC dispersion coatings has been investigated. The phosphorus content in the alloys, which was regulated by phosphorous acid content in the sulfamate bath, exerted a decisive influence on the stress in the electrodeposits. The optimum phosphorus content in the matrix alloy for obtaining the highest abrasion resistance of the Ni-P-SiC composite coatings was found to be 3.5%. It is suggested that the resistance of the composite coatings to abrasion is due not to their hardness, but to the stress in the electrodeposits. It is concluded, therefore, that the baking after deposition may be avoided.

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The effects of Al flake powder in polyvinyl chloride (PVC) film on the weatherability of PVC coated steel sheet were studied. The degradation of PVC film after weathering tests was estimated by surface appearance, residual plasticizer, oxidative degradation and decrease of the average molecular weight (Mw) of the PVC. It was found that there were close correlations among in the change in the surface appearance of the PVC film after weathering tests, the oxidative degradation and the decrease in the Mw of PVC. PVC film containing Al flake powder of more than 10 PHR showed weatherability superior to that of commercial PVC film containing TiO₂ pigment of 12 PHR. The results of radical measurement by electron spin resonance and heat shrinkage of PVC film indicated that the role of the Al flake powder in PVC film was the reflection of ultraviolet rays from its surface and the suppression of film shrinkage

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