Microthrowing power of electrolytes for the deposition of nickel-iron alloys. I. Components determining the levelling effect of nickel-iron plating electrolytes

The microthrowing power of an electrolyte for plating nickel-iron alloy deposits containing organic additives of the Classes I and II was investigated in an effort to determine the contribution of each component of the system. The levelling versus concentration relationships were evaluated for each additive and the iron ions in the electrolyte both separately and in combination. The results show that the main levelling additives in this system are the brightener Class II as well as the iron component in the presence of saccharin.     

Microthrowing power of electrolytes for the deposition of nickel-iron alloys. II. Levelling effect of iron in nickel-iron electrolytes and its microdistribution in the alloy coating

Investigations were aimed at demonstrating and clarifying the levelling effect of the iron component in a saccharin-containing nickel-iron alloy plating electrolyte. The results provide evidence that levelling probably follows the adsorbtion-diffusion mechanism proposed by Kardos and Foulke, as well as by Edwards and Watson. Microprobe analysis shows that the microdistribution of iron in the alloy deposit is not uniform, its content being higher in the alloy plated on the micropeaks of the cathode profile. A quantitative evaluation of the non-uniform distribution of iron is proposed and a linear empirical relationship has been established between this calculated value and levelling determined by profilometric measurements.