Abstract
This paper describes the studies on the limiting current density in nickel plating.
The experiments were carried out under the following conditions.
Composition of electrolyte: nickel sulfate 300g/l
and boric acid 30g/l
Electrolyte temperature: 20-60°C
Interval between electrodes: 1mm
Flow speed of electrolyte: 0-10m/sec.
As the results of experiments, it was found that the limiting current density in nickel plating can be expressed by the following equation:
il=1.7×106nFCD2U1/2/1-α
where U=Flow speed of electrolyte
D: Diffusion coefficient
F: Faraday constant
C: Concentration of nickel sulfate
α: Transport number
il: Limiting current density
The above equation corresponded well with the results of experiments at Reinolds number of less than 5000. However, the measured values of il were higher than those calculated from the above equation at speeds in the range of 0-1 or beyond 5m/sec.
