スルファミン酸浴におけるスルファミン酸イオンの陽極酸化とＮｉ電析に及ぼす影響

Abstract

Anodic oxidation behavior of sulfamate ions during the electrodeposition of Ni from sulfamate baths was investigated using Pt, Ni and Ni-S anodes. The following results were obtained ; (1) The oxidation products of sulfamate ions showed an absorption peak at 245-250 nm in UV spectra and the absorbance was changed depending on the anode potential. (2) At potentials less noble than 0 V vs. NHE, no anodic oxidation products were formed, while the amount of anodic oxidation products was significantly increased when the anode was polarized to a greater noble potential than 0 V. (3) In the presence of Cl- ions in the baths, the Ni-S anode was maintained at potentials less noble than 0 V under most electrolysis conditions. (4) The content of S in the electrodeposited Ni was increased in proportion to the concentration of the anodic oxidation products in the baths. (5) By increasing the content of S, the deposited Ni became finer in size and showed the feature of unoriented dispersed type with high hardness.