Surface of porous catalyst film prepared by coating and diffusion treatment was investigated. Fe-Al alloy was formed on the surface of iron plate by aluminum coating. The thickness of alloy layer increased by the heat treatment. The alloy plate was treated by 10wt% NaOH solution at 80°C. The skeleton plate thus obtained was dried and oxidized in a desiccator. The catalyst was used for the reduction of NO with NH₃. The vertical cross sections of the coated and heat-treated specimens were analysed by EPMA. From the experiments of Mercury pressure porosimeter and nitrogen absorption at the liquid nitrogen temperature, pore size distributions of catalysts were measured. The catalysts were found to be Fe₃O₄ from the X-ray diffraction analysis. Fe₂Al₅ (η) phase was formed at the interface between Fe-Al. The growth rate of η phase was W=kt^1/2 and the following values were obtained; temperature dependent factor A=8.2×10^-6 (m²/sec), heat of loosening Q=37.3(Kcal/ mol). η phase growth is due to the interdiffusion by the heat treatment. The temperature dependence equation of the growth rate of η phase is D=9.6×10^-1 exp (-4.0×10⁴/RT) (m²/sec). Pore size distributions can be interpreted in terms of bi-disperse pore model. η phase thickness is proportional to the specific surface area of catalyst and to the catalytic activity.

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Integral colored films were investigated in ammonia-fluoride baths containing metal salts by using alternating current and direct current superimposed process. A yellow film was formed in the bath containing silver salts at DC:AC=1.5A/dm²:3A/dm², a black film was formed in the bath containing cobalt salts and nickel salts at DC:AC=1.5A/dm²:3A/dm² and 1A/dm²:3A/dm², and a brown film was formed in the bath containing ferrous salts and zinc salts at DC:AC=1.5A/dm²: 3A/dm². The film thickness increased linearly with electrolytic time. Distribution of nickel in the pores of films was determined by electron probe microanalysis, and deposited nickel was observed only in the pore bottoms. The properties of the integral colored films formed using alternating current and direct current superimposed process were equal or excellent as compared with those formed by alternating current process.

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Alloy electrodeposition was made in aqueous solution of K₄P₂O₇ containing KAg (CN)₂ and Sn₂P₂O₇ to put silver-tin alloy plating to practical use. Cathode potential on silver-tin alloy deposit was -0.55V, and limiting current density was at nearly -1.10V. Limiting current density on silvertin alloy deposit shifted about 6.3 times that of Ag⁺ solution and about 2.5 times that of Sn²⁺ solution to the higher current density. Compared with alloy deposit pontential, the electrodeposition potential of silver in Ag⁺ solution was more noble and that of tin in Sn²⁺ solution was less noble. Silver content in silver-tin electrodeposited alloys was always higher than Ag⁺ concentration in an electrolyte, and tin deposit quantity tended to increase with a small molar ratio of silver concentration in the bath, or with high K₄P₂O₇ concentration and high bath temperature. Tin content increased with increasing a pH in the bath and cathode current density. Cathode current efficiency was 95% without pH effect, but increasing current density tended to decrease current efficiency. An adhesive, smooth and silver white semi-bright surface was observed in silver-tin alloy coats under the electrolytic conditions of the Ag/Sn molar ratio being 0.093/0.126, 0.7mol·l^-1 K₄P₂O₇ concentration, at pH 9.0, 25°C and a current density of 10mA·cm^-2.

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Immersion boriding of a few sintered ferrous materials by using boric acid and potassium borate as main salt compositions were carried out. The influence of the boriding conditions on layer thickness, and composition, hardness and surface crack of boride were investigated. At the boriding of sintered ferrous materials, a single phase Fe₂B or two-phase FeB, Fe₂B boride layer was formed. At the boriding of sintered materials for 1 hour between 800°C and 950°C, formed boride was only Fe₂B. The influence of compositions of sintered materials on layer thickness at 900°C, the thickest layer was obtained with pure iron, and the layer thickness of another specimens were not so noticeable. The microhardness of boride layer was about 1400 to 1900 for HV(0.1), and difference of hardness of formed boride on the Fe, Fe-1.5% Cu-0.6%C and Fe-2.0%Cu samples was not so noticeable. Surface crack of formed boride with bonding of sintered materials was depended upon the layer thickness and composition of boride. With increasing thickness of boride layer, and two-phase of FeB, Fe₂B than a single phase Fe₂B, surface crack of boride layer tended to become more yield. In case of the layer thickness of boride less than 40μm, surface crack of boride did not yield. Influence of compositions of sintered materials on crack of boride layer surface, the largest crack was obtained with Fe-1.5%Cu-0.6%C sample, and in due order Fe, Fe-2.0% Cu sample.

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By the analogical method using the conducting paper, cell voltage and current distributions at electrodes in Hull cell are measured as a function of the cathode inclination angle (α) and the distance between anode and cathode electrodes. The effect of auxiliary anode and cathode, and current shield on the current distribution at cathode in Hull cell and Cell voltage are also measured. The current distribution at cathode is expressed as a straight line on the semi-log plot for the current vs. distance along the cathode only in the case α=39°. The longer the distance between electrodes, the higher the cell voltage, eventhough the distance between electrodes has little effect on the current distribution at cathode. The auxiliary cathode and shield scarcely improve the current distribution at cathode and only increase the cell voltage.

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