Jacek Jędruch

Bio: Jacek Jędruch is an academic researcher from AGH University of Science and Technology. The author has contributed to research in topics: Adsorption & Surface charge. The author has an hindex of 1, co-authored 1 publications receiving 6 citations.

Codeposition of SiC particles with electrolytic cobalt in the presence of Cs+ ions

Abstract: Electrodeposition of SiC particles with cobalt matrix in the presence of cesium ions was studied. The influence of Cs + concentration (0–37.6 mM) on the cathodic polarization curves was determined in galvanostatic and potentiodynamic measurements. It was found that the presence of Cs + in the solution enhanced adsorption of Co 2+ ions on SiC, but preferential cesium adsorption occurred simultaneously. The last phenomena resulted in cesium incorporation in the composite coating. Surface charge of SiC powder and amounts of functional groups on SiC surface were determined. The particles incorporation into deposits was only little dependent on cesium concentration in the bath. Structure of the composite coatings was studied by microscopic observations. Microhardness of the deposits was also determined.

Effect of Co content on electrodeposition mechanism and mechanical properties of electrodeposited Ni–Co alloy

Abstract: Ni-Co coatings with various cobalt contents were electrodeposited from modified Watts bath. The effect of cobalt content on electrodeposition mechanism of the coatings was studied by electro-chemical impedance spectroscopy method (EIS). Surface morphology and crystallographic structure of the coatings were investigated by means of SEM and XRD. Mechanical properties of the coatings were determined using Vickers microhardness and tensile tests. It was found that with increasing the Co 2+ ions in electroplating bath, the charge transfer resistance ( R ct ) of Ni–Co film increased whereas the Warburg impedence decreased. This may be due to enhancement in coverage of cathode surface by Co(OH) 2 and higher diffusion rate of metal ions towards cathode surface, respectively. Also, with increasing the cobalt content in the bath, cobalt content in the alloy coating increased anomalously and (111) texture consolidated gradually. With increasing the cobalt content up to 45% in alloy coating, the grain size decreased and consequently, hardness and strength of the alloy increased. Further enhancement of cobalt content up to 55% led to a little decrease in hardness and strength. The maximum ductility was observed for Ni–25%Co coating due to relatively small grain size and compact structure.

Электроосаждение композиционных покрытий

Abstract: Российский химико-технологический университет им. Д.И. Менделеева, Миусская пл., 9, Москва, Российская Федерация, 125047 Отдел научной информации по проблемам химии и химической технологии, ВИНИТИ РАН, ул. Усиевича, 20, Москва, Российская Федерация, 125190 Институт физической химии и электрохимии им. А.Н. Фрумкина, Ленинский пр -т., 31, к.4, Москва, Российская Федерация, 119071 E-mail: vin-62@mail.ru*

The effect of Cs+ ions on codeposition of SiC particles with nickel

Abstract: Electrodeposition of SiC particles (technical powder) with nickel matrix in the presence of cesium ions (0–376 mM) was investigated The influence of Cs+ concentration on cathodic polarization curves was determined in galvanostatic and potentiodynamic measurements The presence of Cs+ in the solution enhanced in some extent adsorption of Ni2+ ions on SiC, but preferential cesium adsorption occurred simultaneously The last phenomenon resulted in cesium incorporation in the composite coating The particle content in the deposits (16–24 vol%) was governed by the amount of nickel ions adsorbed on SiC Structure of the composite coatings was studied by microscopic observations At highest Cs+ concentrations, incorporation of small SiC grains was inhibited Microhardness of deposits (390–800 HV) was directly dependent on the SiC content in the coatings

Studies on the Codeposition of SiC Nanopowder with Nickel, Cobalt, and Co-Ni Alloys

Abstract: Electrodeposition of SiC nanopowder (approximately 120 nm) with nickel, cobalt, and Co-Ni alloy matrix was studied. It was found that particles suspended in the bath affect slightly the reduction of metallic ions. Incorporation of the ceramic particles was governed mainly by the morphology of the matrix surface, while no strict correlation between the amount of cobalt ions adsorbed on the powder and the SiC content in the composites was found. Microhardness of nickel deposits was HV, while for cobalt-rich coatings (84–95 wt.% Co) the values were in the range of 260–290 HV, independently of the SiC content in the coatings. Fine-grained nickel deposits were characterized by good corrosion resistance, while cobalt and Co-Ni alloys showed high corrosion current densities.

Codeposition of SiC particles with cobalt matrix

Abstract: Purpose: The aim of this work was to determine the influence of current density and SiC powder concentration in the bath on the kinetics of the cathodic reaction as well as composition, morphology, microhardness and corrosion resistance of Co/SiC composite coatings. Design/methodology/approach: Co/SiC composite coatings were deposited from a chloride-sulfate bath at two current densities (0.5 and 1 A/dm 2 ) and various SiC powder concentrations (10-50 g/dm 3 ). SiC content in the composites was determined by an image analysis. The microstructure was studied using optical and atomic force microscopes. Microhardness and corrosion resistance (in H 2 SO 4 ) of the deposits were determined as a dependence on the SiC content in the coatings. Findings: SiC incorporation increased (15-36 vol%) under powder addition to the bath, but increase in the current density enhanced cobalt matrix deposition. The last one resulted in lower particles contents in the coatings accompanied by an increase in the current efficiencies. Microscopic observations of the coatings revealed uniform distribution of the particles within matrix. Microhardness of the composites was 200-280 HV. Corrosion resistance of the coatings was improved a little at higher SiC content in the composites.