Lidia Burzyńska

Bio: Lidia Burzyńska is an academic researcher from AGH University of Science and Technology. The author has contributed to research in topics: Cobalt & Copper. The author has an hindex of 7, co-authored 17 publications receiving 278 citations.

Electrodeposition of nickel/SiC composites in the presence of cetyltrimethylammonium bromide

Abstract: Electrodeposition of SiC particles with nickel matrix in the presence of cetyltrimethylammonium bromide (CTAB) at two current densities was carried out. Surface chemistry (amount of acidic and basic superficial groups, surface charge, Ni2+ and Br− adsorption) of the SiC powder in the presence of various CTAB amounts (0–1.1 mM) was studied. Cationic surfactant inhibited adsorption of cations and enhanced adsorption of anions on the positive charged carbide surface, but Br−/Ni2+ molar ratios for adsorbed ions were higher than in the bath. It was attributed to the CTAB adsorption realized predominantly by hydrophobic interactions between aliphatic chain of the molecule and SiC surface with the positive head group of CTA+ pointed toward the bulk solution. Increased SiC incorporation to the composite coating with CTAB addition was observed. Correlation between current efficiency and Br−/Ni2+ molar ratios for ions adsorbed on SiC was found. The influence of CTAB concentration on the cathodic polarization curves was also determined. Structure of the composite coatings was studied by microscopic observations. Microhardness of the fine-grained metal matrix composites was also determined.

Electrodeposition and heat treatment of nickel/silicon carbide composites

Abstract: Electrodeposited Ni/SiC composite coatings were obtained in a Watts-type bath. The effect of fine SiC particles on polarization curves of the cathodic reduction of nickel ions was discussed. The incorporation of the particles into the deposit with respect to current density and SiC concentration in the bath was tested. Cathodic current efficiencies were also calculated. Structure of as-plated and heat-treated Ni/SiC composites were examined by means of metallography observations as well as scanning and transmission electron microscopy methods. Two phase transformations in the temperatures range of 20–700 °C were found. For annealed samples, Ni 2 Si and Ni 3 Si 2 phases were identified. Hardening of the Ni/SiC composites as a function of the particle content in the deposit and annealing temperature was determined by means of the microhardness testing method.

The influence of electrolysis parameters on the composition and morphology of Co–Ni alloys

Abstract: The influence of cathodic current density, the concentration of Co 2+ ions in the electrolyte, and additional substances (saccharin and sodium lauryl sulfate) on the composition and morphology of Co–Ni alloys were investigated. Research was carried out in a Watts-type bath in the presence of boric acid, as a buffer substance. The circulation speed of the electrolyte was 40 dm 3 h −1 . Cathodic polarisation curves were determined for parent metals and the Co–Ni alloy. It was established that the presence of additives shifts the cathodic potential of alloy deposition towards more negative values. An increase in the cobalt content in the alloy was observed with decreasing of the cathodic current density and increasing of the Co 2+ ions concentration in the bath. Results obtained confirmed the anomalous character of deposition of the Co–Ni alloy. The cathodic current efficiency is dependent mainly on the current density applied, but the direction of changes has not been precisely determined, for it depends on the composition of the electrolyte. Using diffractional X-ray and micro X-ray analyses, it was determined that single-phase deposits with an fcc lattice for the whole investigated range of current density and electrolyte composition were obtained. In the presence of additives there were obtained fine-grained, bright alloys which adhered well to the substrate.

Hydrometallurgical recovery of copper and cobalt from reduction-roasted copper converter slag

Abstract: The paper is concerned with a simple hydrometallurgical method for selective recovery of copper and cobalt from industrial copper converter slag. The following consecutive stages are proposed: roasting of the slag in reduction conditions to produce Cu–Co–Fe–Pb alloy, electrolytic dissolution of the alloy in an ammonia–ammonium chloride solution, ammoniacal leaching of the slime, selective copper and cobalt electrowinning. Cu27–Co6–Fe64–Pb1.5 alloy was a five-phase system and did not dissolve uniformly during electrolysis. This resulted in the separation of the metals, wherein iron remained in the slime, while copper and cobalt were components of slime, electrolyte and cathodic deposit. A mechanism of the alloy dissolution was developed. A series of secondary processes took place in the system: precipitation of iron compounds, copper cementation with cobalt and iron; adsorption of copper and cobalt ions on the iron precipitates. Final products were metals of high purity (99.9% Cu, 92% Co).

Influence of the composition of Cu–Co–Fe alloys on their dissolution in ammoniacal solutions

Abstract: The dissolution of a range of Cu–Co–Fe alloys in ammoniacal solutions was examined. High-copper alloy dissolution was possible in ammonia–ammonium sulphate solution with the addition of copper(II) ions. Such a process was spontaneous, selective and efficient with almost all copper dissolved. No iron was found in the solution and the residual slimes contained iron and cobalt. Low-copper alloys were unaffected by the copper(II) ions but dissolved during electrolysis in ammonia–ammonium chloride solution with an anodic current efficiency of 97%. Under these conditions, almost all iron and copper transferred into the slimes and the cobalt was plated onto the cathode.

A review of the electrodeposition of metal matrix composite coatings by inclusion of particles in a metal layer: an established and diversifying technology

Abstract: Following a brief overview of their history, which dates back to the 1920s with marked developments during the 1960s and 1970s, the principles of composite coatings, achieved by including particles dispersed in a bath into a growing electrodeposited metal layer, are considered. The principles and role of electroplating compared to other techniques for realising such coatings, are considered. A good quality particle dispersion (often aided by a suitable type and concentration of surfactants) appropriate choice of work-piece shape/geometry and controlled agitation in the bath are seen to be prerequisites for achieving uniform coatings having a well-dispersed particle content by electroplating. Examples are provided to illustrate the influence of bath composition and plating conditions on deposit properties. Engineering applications of included particle composite layers are illustrated by examples of hard ceramic, soft ceramic and polymer inclusion composite coatings from the recent literature. Current trends in the development of composite plated coatings are summarised and their diverse applications are seen to include the use of finely structured (especially nanostructured) and functionally active particles together with hybrid and more complex, e.g. hierarchical, structures for applications ranging from tribology to speciality electronics, magnetic and electrochemical energy conversion materials.

Microstructure and tribological properties of electrodeposited Ni-Co alloy deposits

Abstract: Ni–Co alloys with different compositions and microstructures were produced by electrodeposition. The effects of Co content on the composition, surface morphology, phase structure, hardness and tribological properties of Ni–Co alloys were investigated systemically. Results showed that the morphology and grain size of alloys are mainly influenced by the Co content and the phase structure of Ni–Co alloys gradually changed from fcc into hcp structure with the increase of Co content. The hardness of Ni–Co alloys with a maximum around 49 wt.% Co followed the Hall–Petch effect. It was found that the improvement of wear resistance of Ni-rich alloys with hardness increase fits Archard's law. In addition, the Co-rich alloys exhibited much lower friction coefficient and higher wear resistance when compared with Ni-rich alloys. It has been concluded that hcp crystal structure in Co-rich alloys contributed to the remarkable friction–reduction effect and better anti-wear performance under the dry sliding wear conditions.

Graphene–nickel composites

Abstract: Graphene/nickel composites were prepared by electrodeposition in a nickel sulfamate solution with graphene oxide (GO) sheets in suspension. Raman spectra demonstrated that the GO sheets had been reduced during the electrodeposition process and the graphene content was 0.12 wt%. X-ray diffraction patterns showed the preferred orientation of nickel growth changing from (2 0 0) to (1 1 1) in the composites. Transmission and scanning electron microscopy images were used to help explain how the introduction of graphene substrates leads to the change of preferred orientation. Measurements showed the thermal conductivity of the composites to be about 15% more than that of pure nickel electrodeposits. Significant improvement was also demonstrated in the hardness measured by nanoindentation.

Nickel–cobalt electrodeposited alloys for hydrogen evolution in alkaline media

Abstract: A study on the electrocatalytic performances of nickel–cobalt alloys for hydrogen evolution in alkaline media has been carried out. After preparing, by electrodeposition on aluminium net supports, Ni–Co alloys of various compositions ranging from 0 to 100% Ni, the alloys were examined by polarization measurements, to evaluate their discharge potential and Tafel parameters. Moreover a durability test has been done on the alloys showing, among all, the best performance. The hydrogen over-potential appears to be lower in the case of Ni concentrations ranging between 35 and 59 weight percent. The synergism among the nickel catalytic properties, having low hydrogen over-potential and high hydrogen adsorption of cobalt, is best realized in this conditions and allow obtaining a largest value of exchange current density.

Recent developments in the electrodeposition of nickel and some nickel-based alloys

Abstract: The numerous theoretical and practical studies of the electrodeposition of nickel and its binary and selected ternary alloys with copper and cobalt over the last 10–15 years are reviewed. The reported mechanisms of the electrodeposition processes and accompanying evolution of hydrogen are considered. The complex influence of different bath compositions, pHs, current densities or potential ranges and temperature on the formation of single or multiple deposition layers are compared. The determination of the structure and morphology of the deposits on different substrates, including solid surfaces and particulate materials, using a range of analytical techniques are reported.