This work presents the studies on the electrochemical process of thin palladium layers formation onto electrodeposited cobalt coatings. The suggested methodology consists of the preparation of thick and smooth cobalt substrate via galvanostatic electrodeposition. Cobalt coatings were prepared under different cathodic current density conditions from acidic bath containing cobalt sulphate and addition of boric acid. Obtained cobalt layers were analyzed by x-ray diffraction to determine their phase composition. Freshly prepared cobalt coatings were modificated by the galvanic displacement method in PdCl2 solution, to obtain smooth and compact Pd layer. The comparison of electrocatalytic properties of Co coatings with Co/Pd ones enabled to determine the influence of Palladium presence in cathodic deposits on the hydrogen evolution process.
This paper presents the results of experiments on metallization of plastic elements produced using 3D printing technology from the light-hardened resins. The obtained coatings were bimetallic (Cu/Ni). The first step of metallization was the electroless deposition of copper. The second one was electrodeposition of nickel on the previously prepared copper substrate. The parameters of 3D prints preparation and metallization processes were deeply investigated. The etching of plastics substrates and duration of electroless metallization of 3D prints by copper were analyzed. In the next step the influence of nickel electrodeposition time was investigated. The coating were analyzed by XRD method and morphology of surface was analyzed by scanning electron microscopy (SEM). The thickness of coatings was calculated based on mass differences and measured by using optical microscopy method. The optimal parameters for both processes were specified.