金属表面技術
Online ISSN : 1884-3395
Print ISSN : 0026-0614
ISSN-L : 0026-0614
28 巻, 12 号
選択された号の論文の9件中1~9を表示しています
  • 小西 三郎
    1977 年 28 巻 12 号 p. 612-620
    発行日: 1977/12/01
    公開日: 2009/10/30
    ジャーナル フリー
    Laboratory studies have been made on chromium plating from the low concentration bath containing CrO3 50g/l, H2SO4 0.5g/l, and Na2SiF6 0.5g/l. Compared with the deposits from the conventional high concentration bath, the chromium deposits from the low concentration bath were almost similar in respect of bright area, throwing power, covering power, current efficiency, hardness, crack and corrosion resistance etc. Also, the industrialization of chromium plating from the low concentration bath has been made successfully in a full automatic batchtyped and a handtyped plating process in a plating factory. In the fomer process, Sargent bath constituents could be reduced to CrO3 100g/l, H2SO4 1g/l by stopping replenishment of CrO3 and H2SO4. In the latter case, the bath was diluted with water to the above mentioned low concentration. Consequently, the amounts of CrO3 supplied, rinse water, chemicals for effluent treatments, and sludge produced were remarkably decreased with lowering concentration of CrO3 in the chromium plating bath.
  • 糸井 康彦, 内山 郁夫, 佐藤 栄一
    1977 年 28 巻 12 号 p. 621-624
    発行日: 1977/12/01
    公開日: 2009/10/30
    ジャーナル フリー
    This paper deals with the composition and electrochemical properties of the γl and γs-layers constituting the boehmite films on Al. The boehmite films were produced by soaking Al specimens, previously treated with a H2SO4-HNO3 solution, in boiling distilled water for 20 minutes. The γs-layer next to the metal was exposed by dissolving the outer γl-layer in a boiling phosphoric acid-chromic acid solution (20g of CrO3 and 35ml of 85% H3PO4 in 1l of distilled water) for 10 minutes; the γs-layer was found to be almost non-soluble. It was also found in a 0.5M NaCl solution that the corrosion potential of the specimen covered with the original (γls) boehmite film is -1.1V (vs. S.C.E.), and the value is about 0.3V more negative than that measured after the γs-layer has been exposed. This is consistent with the fact that the presence of the γl-layer causes an increase in cathodic polarization and inhibits the corrosion of the substrate metal. Examinations of the composition of the layers by X-ray diffraction and electron diffraction show that the γi-layer and γs-layer consist mainly of γ-AlOOH and a-Al2O3, respectively.
  • 伊藤 征司郎, 滝谷 昭, 村先 寿一, 桑原 利秀
    1977 年 28 巻 12 号 p. 625-628
    発行日: 1977/12/01
    公開日: 2009/10/30
    ジャーナル フリー
    The purpose of this paper is to investigate the esterification of the surface hydroxyl groups of hydrated alumina powder (main constituent being boehmite) with normal chain alcohols, for hydrophobing of anodic oxide film on aluminum. Esterification was carried out by the reflux method. The surface hydroxyl groups of the hydrated alumina powder was esterifled with alcohols as -OH→-OR (R: alkyl group), and the amount of alkoxy group calculated from the data of ultimate analysis was about 4-5×10-4mol/g. The esterified powders showed hydrophobic properties. They floated on water, and this effect was remarkable in the case of treatment with a mixed solution of 1-dodecanol and dodecane, where the treated powder never sedimented in water. The surface hydrophilicity of the powder wasdecreased to about 1/3 of that of the original powder.
  • 青木 公二, 鷹野 修, 石橋 知, 林 忠夫
    1977 年 28 巻 12 号 p. 629-633
    発行日: 1977/12/01
    公開日: 2009/10/30
    ジャーナル フリー
    A study has been made of the effect of tin and phosphorus content of the bath on the properties of electroless nickel-tin-phosphorus alloy deposits obtained from ammonia alkaline bath. The alloy deposits containing up to 1.0% tin and 3.4-5.4% phosphorus can be obtained by an addition of sodium stannate to the plating bath. The deposition rate of the alloy containing 0.25% tin was the lowest, because tin reacted as an inhibitor on the nickel surface. It was also found that the corrosion resistance of the nickel-tin-phosphorus deposit containing 0.46% tin and 3.97% phosphorus was most enhanced in 1N sulfuric acid by the presence of tin and phosphorus.
  • 廣地 通明, 吉村 長蔵
    1977 年 28 巻 12 号 p. 634-637
    発行日: 1977/12/01
    公開日: 2009/10/30
    ジャーナル フリー
    The structure of anodized film on aluminum formed in alkaline bath containing hydrogen peroxide at constant voltages has been studied by electron microscopy. Electron micrographs of the section of anodized film showed that the pores were branched. This structure is much different from the vertical and regular structure proposed by Keller and others. It was found that the pores on the surface increased in size and joint to each other in proportion to anodizing time and that the columns in the wall were widened with a rise in electrolytic voltage. Thickness of the barrier layer was about 12Å/V and not greater than that of the barrier layers formed in ordinary sulfuric acid baths.
  • 吉村 長蔵, 野口 駿雄
    1977 年 28 巻 12 号 p. 638-643
    発行日: 1977/12/01
    公開日: 2009/10/30
    ジャーナル フリー
    Dyeing affinity, cell size, and cross-section of the anodized films produced in alkaline solutions (0.1M-NaOH, 0.1M-Na2CO3, 0.1M-Na3PO4, and NH4OH-NH4F system bath) were compared with those of the films produced in H2SO4 solution. The surface and cross-section of the thin anodized films which were obtained by complete anodizing of aluminum foils and also the surface of the substrates from which the oxide films had been removed were observed by SEM. The pore walls in the anodized films formed in NaOH and Na3PO4 were uneven compared with those in the films formed in NH4OH-NH4F or H2SO4. Observation of the surface and cross-section of the films prepared in Na3PO4 revealed deposits which seemed to be phosphates or hydroxides. It was found that the bottom size of the cell was linearly proportional to the electrolytic voltage regardless of the bath composition. On the other hand, the differences in permeability, dyeing affinity, and adsorption amount of the dyestuffs (acid, basic, direct and mordant) were determined by mesuring the reflection absorbance of the dyed films and by a colorimetric method. Dyestuffs were adsorbed to a greater extent in the film prepared in Na3PO4 than in any other films produced in alkaline solutions. The amount of the adsorbed dyestuff decreased in the order of the following kinds of films: Na3PO4>NaOH>Na2CO3>NH4OH-NH4F>H2SO4 films. The amount of dyestuff passed through the thin anodized film produced in NH4OH-NH4F was about two times as much as that produced in H2SO4. SEM observation and dyeing tests suggest that the anodized films formed in alkaline solutions have larger pores and cells as compared with the films anodized in H2SO4.
  • 石橋 喜代司
    1977 年 28 巻 12 号 p. 648-650
    発行日: 1977/12/01
    公開日: 2009/10/30
    ジャーナル フリー
  • 1977 年 28 巻 12 号 p. 658a
    発行日: 1977年
    公開日: 2009/10/30
    ジャーナル フリー
  • 1977 年 28 巻 12 号 p. 658b
    発行日: 1977年
    公開日: 2009/10/30
    ジャーナル フリー
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