モデル電極を用いたAlへの無電解Niめっき初期過程の解析

抄録

In order to reproduce the initial process of the electroless plating of Ni on Al prepared with a double zincate pretreatment, a model electrode was prepared in which a small Zn tip was pressed to an Al plate. The immersion potential of the model electrode during plating was around-1 V for the first few seconds, which corresponds to the period of Zn dissolution, and then shifted to about-0.6 V which corresponds to electroless Ni plating on the Ni-P layer. By applying pressure to the Zn tip, it became possible to plate the Al specimen without zincate pretreatment. However, an anomalous deposition of Ni was sometimes observed around the Zn tip. This anomalous deposition was found to be formed at damaged areas such as the area to which the Zn tip was applied and the edges of the specimen. When these areas were coated, the time at which Ni deposition began was delayed and the distribution of Ni on the surface became uniform. Based on these results, the function of zincate pretreatment in electroelss Ni plating was considered.