Abstract
Pulse plating of Fe-Ni alloy in a modified Watt's bath was investigated with regard to the effect of pulse conditions on partial polarization curves, current efficiency and the composition of deposit. The partial currents for deposition of iron and nickel were affected by pulse conditions independently each other. Since concentration polarization is minimized in pulse plating, hydrogen evolution was inhibited and hence the current efficiency of alloy deposition, especially that for iron deposition, was greatly improved in comparison to the d-c plating. Therefore, in order to obtain the deposit of permalloy composition (Fe: 20mass%), the concentration of ferrous ion in the bath should be reduced by the factor 1/3 of that for d-c plating. It is concluded that pulse plating yields Fe-Ni alloy deposit of a stable composition with a bright surface of fine crystal grain on an optimum pulse condition.
