Adsorption of the Components of a Chrome-Plating Electrolyte on Dispersed Corundum Particles

Abstract

In the process of deposition of composite electrolytic coatings, we have discovered two kinds of adsorption playing an essential role in the formation of these coatings, namely, the adsorption of dispersed particles on the cathode and the adsorption on the surfaces of these particles in the process of their introduction in the electrolyte. The hypothesis about the influence of the nature of dispersed phase on the formation of protective coatings is experimentally confirmed by the results of IR-spectrometric and X-ray phase diffraction investigations. It is shown that the thickness of the layer of ions of the components of chromium electrolytes adsorbed on the surfaces of corundum particles depends on the absorption coefficient, which, in turn, depends on the number of element of the dispersed phase in Mendeleev's periodic table of elements and on the atomic weight. Hence, the greater the atomic weight of an element of the dispersed phase, the smaller the thickness of the adsorbed layer. If the dispersed phase has a molecular structure, then the thickness of the layer is determined by the absorption coefficient additively formed by the atomic coefficients of elements that form the analyzed molecule.