Electrochemical Cr-Ni-Al_2O_3 Composite Coatings Part I: Some Aspects of the Cpdepositlon Process

摘要

Codeposition of Al_2O_3 particles and Cr-Ni alloy (4-90 wt percent Cr) from trivalent N,N-dimethylformamide electrolyte was studied. By means of image analysis, particle amounts and sizes in composite coatings were determined, depending on Al_2O_3 concentration in the electrolyte, current density, pH and matrix composition. Methods such as electrolyte spectroscopy in the UV and visible ranges, IR spectroscopy and ESCA of Al_2O_3 powder, as well as digital x-ray mapping, were shown to be promising for examination of particle behavior in the electrolyte, and for adsorption of particles on the cathode surface. The mechanism of particle codeposition is discussed.