The Effect of Superimposed A.C. on D.C. in Electrodeposition of Ni-Fe Alloys

The effect of superimposing a sinusoidal alternating current on a direct current during electrodeposition of Ni-Fe alloys is discussed in terms of the following factors: (a) maintaining the pH at the electrode equal to that of the bulk electrolyte, (b) ionic diffusion processes, and (c) chemical processes in solution prior to electrochemical reduction. The effect of frequency, amplitude, and the ratio of a.c. to d.c. on the composition of electrodeposited alloy are given for acid solutions of different pH and for alkaline solutions of metallic complexes with a variable concentration of complexing agent. The behavior observed can be explained in terms of the factors listed above. In particular, it is shown that by proper choice of conditions, electrodeposited Fe-Ni alloys can be prepared with a uniform composition throughout their thickness. © 1971, by The Electrochemical Society, Inc. All rights reserved.