亜鉛めっきのホイスカー発生と浴中化学種の関係 [in Japanese] Whisker Growth from Zinc Plating versus Chemical Species in Baths [in Japanese]
Access this Article
Search this Article
High concentrations of cyanide and alkali in baths had the objective of lowering whisker growth in zinc plating, but the mechanism and suitable bath composition remain to be clarified.<br>We studied chemical species concentrations, taking the ion balance into consideration, and found that the carbon content in zinc plating, and the amount of zinc cyanide complexes and free cyanide ions in baths are related to whisker growth. Zincate ions are related to the electrodeposition rate but not to whisker growth. The ratio of zincate ion to zinc cyanide complexes in the cyanide system we studied, is closer to the work of Hasko and Kunkel indicated in the standard cyanide system [Zn(OH)<sub>4</sub><sup>2-</sup>]:[Zn(CN)<sub>4</sub><sup>2-</sup>]≅1:1; in the highcyanide system [Zn(OH)<sub>4</sub><sup>2-</sup>]:[ZnCN]<sub>4</sub><sup>2-</sup>]≅1:2-3) than to the work of Hull and Wernlund indicated (75 to 90% of zinc in the standard cyanide system was present as zincate ion and the remainder as zinc cyanide complexes).<br>This concentration of chemical species can be used as an index of zinc plating baths control instead of ratio M (NaCN/Zn).
- Jitsumu Hyomen Gijutsu
Jitsumu Hyomen Gijutsu 49(5), 502-506, 1998-05-01
The Surface Finishing Society of Japan