The Annals of “Dunarea de Jos” University of Galati. Fascicle IX, Metallurgy and Materials Science (Sep 2016)
Studies and Researches Regarding the Obtaining and Characterization of Composite Nickel Coatings-Ni/Al2O3, Ni/Kaolin Electrochemically Produced
Abstract
This study presents the composite nickel coatings electrochemically obtained using as disperse phases Al2O3 particles and kaolin. There were used Watts electrolytes, with a pH = 4, current density of 4 A/dm2 , a concentration of the disperse phase of 20 g/l, a speed of agitation of 300 rpm, deposit strokes of 60, 90, 120 minutes. The characterization of those has been done microstructurally and also from the point of view of the film thickness and microhardness. The existing of the disperse phase particles has led to the shrinking of the nickel dimensions of crystalites, which has determined a decrease in roughness and an increase in hardness.