The interrelation between the electrodeposition parameters and surface morphology of nickel coatings in the presence of a growth inhibitor

On the one hand, nickel and nickel coatings are well-studied objects in terms of their wide practical application; on the other hand, the application of various approaches to their production and structuring gives new possibilities for changing their properties. At present, the research activities related to the change in nickel physicochemical properties through nanostructuring are being carried out. Methods and techniques for producing nanostructured materials are very diverse. However, many of them are considered energy-intensive and economically unviable. The work solves the problem of obtaining nickel coatings and changing their properties through electrodeposition from aqueous solutions of electrolytes. The paper studies the effect of additives to a nickel electrolyte on the habit of crystals formed in the coating and, consequently, the nickel coating morphology. The authors used sodium, potassium, and calcium chlorides in the same molar concentration to be additives. During the electrodeposition of coating samples, the substrate nature and the electrolysis regimes changed. The deposition was carried out in the stationary mode of electrodeposition within one or two stages of electrolysis. The authors studied the obtained samples by scanning electron microscopy methods using X-ray diffraction analysis. The study identified that chlorides can significantly change the coating surface morphology. Depending on chloride concentration and deposition regimes, the surface morphology of nickel coatings changes from the three-dimensional cone-shaped structures to the lamellar habit. Chlorides allow forming crystals with pentagonal symmetry as well. The addition of chlorides affects the growth of crystals in certain crystallographic directions (111), which may be the result of their inhibitory effect. The obtained nickel coatings have a regular microrelief.