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Electrodeposition of Iron-Nickel Alloys in Presence of Magnetic Field.

磁场存在下铁镍合金的电沉积。

基本信息

批准号：
01550522
负责人：
FUKUSHIMA Hisaaki
金额：
$ 1.41万
依托单位：
Kyushu University
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1989
资助国家：
日本
起止时间：
1989 至 1990
项目状态：
已结题

项目摘要

The electrodepstion of Fe-Ni alloys which was classified into anomalous type was carried out using sulrate solutions to make the codeposition mechanism clear. All phenomena inherent to the electrodeposition of Fe-Ni alloys were not able to be explained by the hydroxide suppression mechanism based on the ferrous hydroxide precipitated on the cathode due to a rise in pH in the vicinity of cathode, because the partial polarization curve of Ni as well as Fe did not change with the variation of bulk pH and the anomaly appearing in Fe-Ni system was not brought about by the polarization of Ni but depolarization of Fe. And other mechanisms based on ferric hydroxide and deposition overpotential of Ni were not justified. Then, the extent of polarization of Fe due to a decrease in the activity of Fe in the alloys was estimated. Any stable intermetallic compounds were not formed in the deposited alloys. However, since the Fe deposition was significantly depolarized in the codeposition of Fe with more noble Cu, the decrease in the activity of Fe was involved in the appearance of the anomaly in Fe-Ni system to some extent.The composition gradient in the electrodeposited Fe-Ni alloys was investigated by IMA and EPMA. It was indicated that Ni was preferentially deposited at the first stage of the electrodeposition and this phenomenon was able to be explained by the hydroxide supression mechanism. The enrichment of Fe near the deposit surface was also observed and might be caused by the preferential oxidation of Fe.Finally, the effect of magnetic field on the electrodeposition behavior of the alloys was evaluated. It was found that the presence of magnetic field resulted in not only the polarization of the alloy deposition but also the changes in the magnetic properties of the deposits.

用硫酸盐溶液对属于异常型的Fe-Ni合金进行了电沉积，以明确共沉积机理。电沉积Fe-Ni合金所固有的所有现象都不能用基于阴极附近pH升高在阴极上析出的氢氧化亚铁的氢氧化物抑制机理来解释，因为Ni和Fe的偏极化曲线不随体pH的变化而改变，而且Fe-Ni体系中出现的异常现象不是由Ni的极化引起的，而是由Fe的去极化引起的。其他基于氢氧化铁和镍沉积过电位的机理也是不合理的。然后，估算了由于合金中铁的活度降低而引起的铁的极化程度。沉积的合金中没有形成任何稳定的金属间化合物。然而，在Fe与更多的贵金属铜共沉积时，由于Fe的沉积被显著地去极化，Fe的活性的降低在一定程度上与Fe-Ni系统中异常的出现有关。结果表明，镍在电沉积的第一阶段优先沉积，这一现象可以用氢氧化物抑制机理来解释。还观察到Fe在镀层表面附近的富集态，这可能是由于Fe的优先氧化作用所致。最后，对磁场对合金电沉积行为的影响进行了评价。结果表明，磁场的存在不仅导致了合金沉积的极化，而且引起了镀层磁性能的变化。