Recent literature on the electrodeposition of metallic coatings containing nanosized particles is surveyed. The nanosized particles, suspended in the electrolyte by agitation and/or use of surfactants, can be codeposited with the metal. The inclusion of nanosized particles can give (i) an increased microhardness and corrosion resistance, (ii) modified growth to form a nanocrystalline metal deposit and (iii) a shift in the reduction potential of a metal ion. Many operating parameters influence the quantity of incorporated particles, including current density, bath agitation (or movement of work piece) and electrolyte composition. High incorporation rates of the dispersed particles have been achieved using (i) a high nanoparticle concentration in the electrolyte solution, (ii) smaller sized nanoparticles; (iii) a low concentration of electroactive species, (iv) ultrasonication during deposition and (v) pulsed current techniques. Compositional gradient coatings are possible having a controlled distribution of particles in the metal deposit and the theoretical models used to describe the phenomenon of particle codeposition within a metal deposit are critically considered.

Electrodeposition of composite coatings containing nanoparticles in a metal deposit

Pulse and pulse reverse plating—Conceptual,advantages and applications

http://docs.sadrnezhaad.com/papers/261.pdf

Electrodeposition of Ni–SiC nano-composite coatings and evaluation of wear and corrosion resistance and electroplating characteristics

Lithium metal has been regarded as the future anode material for high-energy-density rechargeable batteries due to its favorable combination of negative electrochemical potential and high theoretical capacity. However, uncontrolled lithium deposition during lithium plating/stripping results in low Coulombic efficiency and severe safety hazards. Herein, we report that nanodiamonds work as an electrolyte additive to co-deposit with lithium ions and produce dendrite-free lithium deposits. First-principles calculations indicate that lithium prefers to adsorb onto nanodiamond surfaces with a low diffusion energy barrier, leading to uniformly deposited lithium arrays. The uniform lithium deposition morphology renders enhanced electrochemical cycling performance. The nanodiamond-modified electrolyte can lead to a stable cycling of lithium | lithium symmetrical cells up to 150 and 200 h at 2.0 and 1.0 mA cm–2, respectively. The nanodiamond co-deposition can significantly alter the lithium plating behavior, affording a promising route to suppress lithium dendrite growth in lithium metal-based batteries.

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Nanodiamonds suppress the growth of lithium dendrites.

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.

/pdf/a-review-of-the-electrodeposition-of-metal-matrix-composite-3krnos6cvo.pdf

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

Pure Ni and nickel matrix composite electrocoatings containing micron- and nano-SiC particles (1 μm and 20 nm respectively) were produced under direct and pulse current conditions from an additive-free Watts type bath. The effect of the particle size, codeposition percentage of SiC and type of imposed current on the microhardness as well as on the microstructure of the electrodeposits were investigated. Ni/SiC composite deposits prepared under either direct or pulse current conditions exhibited a considerable strengthening effect with respect to pure Ni coatings. The improved hardness of composite coatings was associated to specific structural modifications of Ni crystallites provoked by the adsorption of H+ on the surface of SiC particles, thus leading to a (211) texture mode of Ni crystal growth. Pulse electrodeposition significantly improved the hardness of the Ni/SiC composite coatings, especially at low duty cycles, in which grain refinement and higher SiC incorporation (vol. %) was achieved. The enhanced hardness of Ni/nano-SiC deposits, as compared to Ni/micron-SiC composites, was attributed to the increasing values of the number density of embedded SiC particles in the nickel matrix with decreasing particle size. In addition, the observed hardening effects of the SiC particles might be associated to the different embedding mechanisms of the particles, which could be characterized as inter-crystalline for micron-SiC and partially intra-crystalline for nano-SiC particles.

Hardening effect induced by incorporation of SiC particles in nickel electrodeposits

Effect of pulse electrodeposition parameters on the properties of Ni/nano-SiC composites

Tribological study of Ni matrix composite coatings containing nano and micro SiC particles

The electrolytic codeposition of ultrafine WC particles (mean diameter of 0.2 μm) from an additive-free nickel Watts' solution by applying both direct (DC) and pulse (PC) electroplating, has been investigated. Electrodeposition of Ni/WC composites was carried out on a rotating disk electrode (RDE) at various rotation velocities. The effect of type current and hydrodynamic conditions of the plating bath on the codeposition of WC particles with Ni matrix has been reported. The crystallographic orientation of nickel matrix, the distribution and the percentage of the embedded particles, were examined as well as the structure and the surface morphology of the produced composite coatings. It was found that electrodeposits prepared at DC conditions and low rotation velocities are highly porous. On the contrary, when applying PC conditions and high rotation velocities, compact deposits with high concentration of embedded WC particles and uniform distribution were produced. It has been observed that the presence of WC particles in the metal matrix imposes an almost random orientation of Ni crystallites along with a reinforcement of [210] orientation. Taking into consideration a surface complexation model and the experimental data, a mechanism of nickel electrocrystallization in the presence of WC particles has been proposed.

Codeposition of ultrafine WC particles in Ni matrix composite electrocoatings

Nickel matrix composite coatings containing micron- and nano-sized SiC particles were prepared in order to study the interdependence of the SiC particles embedding and the deposits 'mechanical behaviour SiC particles of two different sizes, namely 1 μm and 20 nm, were codeposited with nickel from Watts solutions under pulse current conditions. It has been observed that the embedding of SiC particles in the nickel matrix and the pulse current application result in deposits with more uniform particle distribution and better surface morphology than those obtained under direct current conditions. The study of the composite deposits revealed that the microhardness is not only increased by the presence and the reduced size of the particles, but also influenced by the current conditions, i.e. duty cycle and pulse frequency. Moreover, microhardness of the deposits can be further ameliorated by specific thermal treatment.

P. Gyftou

Papers

Hardening effect induced by incorporation of SiC particles in nickel electrodeposits

Effect of pulse electrodeposition parameters on the properties of Ni/nano-SiC composites

Tribological study of Ni matrix composite coatings containing nano and micro SiC particles

Codeposition of ultrafine WC particles in Ni matrix composite electrocoatings

Electrodeposition of Ni/SiC composites by pulse electrolysis : Electrodeposition in Electronics