The anodic polarization behavior of boehmite films produced by soaking aluminum specimens in boiling distilled water for 20 minutes was studied by the measurement of polarization curves in 0.5N NaCl solution immediately after film formation. Effects of solution pH, NaCl concentration and the amount of dissolved oxygen on the limiting current were determined. The results showed that these effects can be ignored. Corrosion potentials of specimens measured immediately after boehmite film formation were found to be less noble than those of specimens stored overnight, while there was little difference in pitting potential. In addition, infrared reflectance spectra (IRRS) of the boehmite films which were polarized at -1.25V, -1.00V and -0.80V, respectively, immediately after film formation were also measured.

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Removal of Cu²⁺ ions from the Watts type nickel plating solution by a weakly basic resin (Sumichelate CR-2) was studied by using batchwise and column methods. The copper ions adsorbed on the resin is desorbed in a 2N-sulfuric acid solution. The amount of Cu²⁺ adsorbed on the resin from the plating solution is represented by Langmuir's adsorption isotherm. The amount of Cu²⁺ adsorbed on the resin in nickel chloride solution is about 7 times that in nickel sulfate solution. Therefore, it is presumed that Cu²⁺ adsorption on the resin in the plating solution results from both the complex forming of Cu²⁺ with the resin and the ion exchange of Cu-chloride complex anion.

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The relation between MnS inclusions and corrosion behavior of stainless steels such as SUS 304 and SUS 303 (AISI) containing 0.004-0.25% S has been investgated in a refreshing drink, NaCl+C₆H₈O₆, NaClO, and HCl solutions by using mainly EPMA, X-ray diffraction analysis and atomic absorption spectrophotometer. Specimens containing more than 0.008% S rusted easily in 100ppm NaClO solution at room temperature for 24hrs, and colored black in 10% NaCl+1% C₆H₈O₆ solution under the same condition. The solutions used were degenerated and at the same time generated a strong smell of H₂S. These tendencies became more pronounced with an increase in S content. In 10-1, 000ppm HCl, 1-30% NaCl+1% C₆H₈O₆ solutions and in a refreshing drink, the amount of Fe and Cr ions increased with an increase in S content of steel. It was found that the preferential dissolution of MnS inclution activated the localized corrosion of steels containing more than 0.004% S, and that increasing amount of MnS accelerated the active corrosion. The corrosion potential of the specimens in the 10% NaCl+1% C₆H₈O₆ solution was nearly proportional to the S content. Results of EPMA and X-ray diffraction analysis revealed that the main cause for the blackening of specimen surface after immersion in the solutions was the redeposition of some kinds of amorophous C and S.

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Anodic oxidation film of aluminium was prepared in sulfuric acid (19.8wt%) with the pulse method. The anodic film (approximately 0.1mm thick) was removed from the substrate by applying the reverse voltage on the substrate. On heating (10°C/min), dehydration of the film occurred at the temperature range of 100° to 400°C and the original semi-transparent gray color of the film became more transparent and less dark. At approximately 950°C, an endothermic decomposition reaction was observed which was followed immediately by a sharp exothermic change. The amorphous- to γ-Al₂O₃ crystallization took place at this temperature and the specific surface area increased sharply. Large part of the sulfur in the film was eliminated in this stage. At approximately 1150°C, the rest of the sulfur was eliminated. The γ-Al₂O₃ began to transform exothermically into α-Al₂O₃, and the film became white and opaque. The specific surface area decreased with increasing temperature. The transformation to α-Al₂O₃ was completed at approximately 1300°C.

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The behavior of Cu (I) in a high-speed electroless copper plating bath was investigated by measuring absorption spectrum of Cu (I) -biquinoline complex. It was found that Cu (I) was formed in Rochelle salt bath regardless of the presence of formaldehyde. The concentration of Cu (I) in this type of plating bath increased with an increase of the Tartrate/Cu (II) molar ratio, leading to the spontaneous decomposition of the bath. Although high-speed electroless copper deposition at higher temperature with satisfactory deposition rate and bath stability was attained by Rochelle salt bath containing the selected additives, ductility of the deposit was far from satisfaction. In EDTA bath, Cu (I) was not detected regardless of the presence of additives. By the combined use of 2, 2′-dipyridyl (10mg/l) with other additives in this bath, high-speed copper deposition was attained with a satisfactory deposition rate, bath stability and high ductility of the deposit. Higher ductility of the deposit and bath stability attained by the EDTA bath compared to Rochelle salt bath was supposed to be due to the fact that no Cu (I) was formed during the deposition reaction in the former type of plating bath. The formation of Cu (I) in different types of plating bath using various complexing agents for Cu (II) was also investigated. Of the 10 types of the bath tested, Cu (I) was detected in 7 baths except in EDTA, DTPA and Quadrol baths. By using the same additives which were proved to be effective in EDTA bath into DTPA and Quadrol baths, high-speed copper deposition was attained with the satisfactory quality of the deposit.

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