NICKEL PLATING BY PULSE ELECTROLYSIS - TEXTURAL AND MICROSTRUCTURAL MODIFICATIONS DUE TO ADSORPTION-DESORPTION PHENOMENA

Nickel growth from an organic-free Watts bath working under d.c. plating conditions is governed by several interfacial inhibitors such as H2, Hads or Ni(OH)2. These inhibitors determine most of the structural or macroscopic properties of the nickel plates. Pulse electrolysis (p.e.) is thus a powerful means of perturbing the adsorption-desorption phenomena occurring at the nickel/electrolyte interface and hence offers an opportunity of preparing deposits exhibiting better properties. Through an analysis of the textural and microstructural changes produced by p.e., we show that molecular inhibitors desorb during the relaxation time, while conversely other inhibitors like Hads or anions are more strongly adsorbed and inhibit the nickel cathodic process. © 1990 Chapman and Hall Ltd.