共查询到20条相似文献,搜索用时 494 毫秒
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将铋离子应用于环氧体系阴极电沉积涂料中,从槽液参数、漆膜性能等方面分析了铋离子代替铅离子作为阴极电沉积涂料催化剂的优势,证明了铋离子应用于阴极电沉积涂料的可行性。 相似文献
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Hydrogen coevolution and permeation in nickel electroplating 总被引:1,自引:0,他引:1
Nickel coatings were electrodeposited onto a steel membrane in a conventional Devanathan cell in order to measure the diffusion rate of hydrogen into the steel substrate during electrodeposition. In most cases a Watts' solution containing various organic additives was used: butyne-2 diol-1, 4; saccharine or thiourea. The structure of the electrodeposits was studied by X-ray and Transmission electron microscopy (TEM). It was shown that the electrodeposition parameters (pH, composition of the bath, additives) have a strong effect on hydrogen permeation. The use of organic additives during Ni plating increased the penetration of hydrogen into the substrate. In particular, sulfur-containing additives cause a fast initial increase of the permeation rate, which is attributable to a high surface concentration of Hads when steel is not totally covered with nickel. By performing permeation experiments with Ni coatings during hydrogen charging from a H2SO4 solution, it was shown that hydrogen permeation through nickel coatings is influenced by their fibre texture and by their grain sizes. A low permeation rate was observed in coatings plated in the presence of butyne-2 diol-1,4, which exhibit a strong 100 texture with large grains and a low density of defects. Conversely, the hydrogen diffusion rate is very high in coatings plated in the presence of thiourea or saccharine. These coatings exhibit a weak texture with very small grains. 相似文献
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In the field of organic coatings, electrodeposition is a technique that holds many advantages over traditional methods of immersion and dispersion, such as low levels of contamination, ease of control and automatization, and high penetration capacity. In this article, the results of the electrodeposition of poly(vinylidene chloride) emulsions on galvanized steel are presented. The operating conditions to form thin, uniform, and adherent films were established. A mathematical model was also developed to predict film growth with time as a function of the process parameters. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 70: 2479–2486, 1998 相似文献
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阴极电泳涂料的研究进展 总被引:3,自引:0,他引:3
介绍了电沉积的原理,阴极电泳涂料和树脂的特点以及阴极电泳涂料的优越性。概述了国内外阴极电泳涂料的现状,重点介绍了几类目前发展较快的阴极电泳涂料,同时指出了阴极电泳涂料今后的发展趋势。 相似文献
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介绍了一种阳离子为锌和锰的磷化液,可以满足阴极电泳配套性要求的无镍磷化工艺。通过对磷化膜膜重,溶出率、结晶形貌、膜成分、电泳后漆膜附着力、抗,中击、耐腐蚀等性能进行比较分析,结果表明在锌离子1.2g/L、锰离子O.8g/L、磷酸根16.0g/L的磷化工艺条件下形成的磷化膜性能指标符合阴极电泳配套要求,与常规锌锰镍系磷化膜基本无差别,性能指标远远高于高锌磷化工艺磷化膜。磷化膜的主要性能指标:P比为85.53%,膜重为3.2g/m2,晶型呈粒状,晶粒大小为3~4μm,磷化膜电泳溶出率为3.7%,附着力和冲击试验均合格,磷化膜与电泳漆复合膜(厚度为20.3μm)盐雾试验500h,单边扩展小于1mm,表面无气泡。 相似文献
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Using cyclic-voltammetric techniques, a pyrophosphate-cyanide electrolyte for the electrodeposition of compact Ag–Sn alloy
coatings is investigated. This electrolyte is suited to further investigations on the alloy composition, structure and properties.
The electrodeposition of coatings with up to 40 wt% Sn is possible from the investigated complex electrolytes. The alloy surpasses
the saturation limit of the silver lattice with Sn and allows the formation of coatings with phase heterogeneity. At high
tin content an ordered spatial distribution of different alloy phases on the cathodic surface can be observed. The pattern
formation in this system looks very similar to the phenomena and structures observed during electrodeposition of other silver
alloys, such as Ag–Sb, Ag–Bi and Ag–In. 相似文献
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M. Ramasri G. S. Srinivasa Rao P. S. Sampathkumaran M. M. Shirsalkar 《应用聚合物科学杂志》1990,39(9):1993-2004
Water-soluble Mannich bases were synthesized from cardbisphenol by Mannich reaction and were characterized by 1H-NMR and 13C-NMR spectroscopic methods. The effect of electrodeposition parameters on the film formation from binders and from the pigmented composition were studied. The polymers gave uniform coatings with good mechanical properties and the pigmented systems exhibited high resistance to organic solvents and excellent corrosion resistance properties. 相似文献
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Bioactive Calcium Phosphate Coating on Sodium Hydroxide-Pretreated Titanium Substrate by Electrodeposition 总被引:1,自引:0,他引:1
Ji-Ho Park Doug-Youn Lee Keun-Taek Oh Yong-Keun Lee Kyoung-Nam Kim 《Journal of the American Ceramic Society》2004,87(9):1792-1794
This study examined the characteristics of calcium phosphate coatings deposited on a NaOH-pretreated titanium substrate by electrodeposition in a modified simulated body fluid (SBF) immediately after electrodeposition as well as after the coatings had been immersed in the SBF for 5 d in order to determine the effects of a NaOH pretreatment on the bioactive coating prior to electrodeposition. The results showed that a dense and uniform coating that consisted of brushite and hydroxyapatite had formed on the NaOH-pretreated titanium substrate by electrodeposition. This coating had transformed to a bonelike apatite during immersion in the SBF. This was attributed to the increased surface area of the modified titanium formed after the NaOH treatment as well as the Na+ ions released from that surface. Therefore, a NaOH pretreatment is recommended as an effective method for preparing a bioactive calcium phosphate coating by electrodeposition. 相似文献