Ni–Al 2 O 3 composite coatings were electrodeposited from a Watts-type bath containing particles in suspension, which were dispersed with the aid of a cationic surfactant hexadecylpyridinium bromide (HPB). The effects of the surfactant on the zeta potential, co-deposition and distribution of Al 2 O 3 particles in nickel matrix, and tribological properties of composite coatings were investigated. Experimental results showed that the addition of HPB could improve the amount of co-deposited Al 2 O 3 particles, reduce the agglomeration of particles and achieve a more uniform distribution of Al 2 O 3 particles in the nickel matrix. The wear resistance of the composite coatings increased with increasing concentration of HPB up to a certain optimum of 150 mg l −1 , beyond which a decreasing trend of wear resistance was observed under dry sliding and oil-lubricated conditions. This is probably due to the increased brittleness of metal matrix when the concentration of surfactant exceeded the optimum.

Effect of surfactant on the electrodeposition and wear resistance of Ni–Al2O3 composite coatings

Micro- and nano-sized SiC particles were codeposited with nickel by electrolytic plating from a nickel sulfamate bath and the effects of plating parameters such as pH of the plating bath, SiC content in the plating bath, and stirring speed on the deposition behaviors of Ni–SiC composite coating layers were studied. The result revealed that the micro-sized SiC particles are more negative than the nano-sized SiC particles in the Zeta potential. The codeposition of SiC can be increased by increasing the SiC content in the plating bath and the pH of the plating bath within the present experimental range. In case of micro-sized SiC particles, increasing stirring speed always lowered the codeposition of SiC. In case of nano-sized SiC particles, the codeposition of SiC showed a maximum at the stirring speed of 100 rpm. The nano-sized SiC particles are more difficult to codeposit than the micro-sized SiC particles and showed rougher plated surface compared with the micro-sized SiC particles, which may be attributable to the agglomeration of nano-sized SiC particles in the plating bath.

Codeposition of micro- and nano-sized SiC particles in the nickel matrix composite coatings obtained by electroplating

Fabrication of Ni–CeO2 nanocomposite by electrodeposition

Nanocomposites containing titania nanoparticles in a nickel matrix have been prepared by means of electrocodeposition from two different types of nickel plating baths, viz. an acidic sulfamate and an alkaline pyrophosphate bath. The surface charge and sedimentation behavior of the titania particles in these electrolytes were characterized by zeta potential and stability measurements. A maximum particle incorporation of 4.3 wt.% titania was found for the alkaline pyrophosphate bath. The structure and mechanical properties of the coatings have been investigated as a function of the particle content. The surface morphology and microstructure of the nickel matrix was significantly altered due to the presence of titania nanoparticles. In the case of both nickel baths, the Vickers microhardness showed a tendency to increase with the amount of particle incorporation. The wear resistance increased with decreasing current density and due to the particle incorporation.

Characterization of electrodeposited Ni–TiO2 nanocomposite coatings

Corrosion resistance and mechanical properties of pulse electrodeposited Ni–TiO2 composite coating for sintered NdFeB magnet

Study of tribological characteristics and wear mechanism of nano-particle strengthened nickel-based composite coatings under abrasive contaminant lubrication

Electrodepositing nickel silica nano-composites coatings

Electrocatalytic action of nano-SiO2 with electrodeposited nickel matrix

This article focuses on the nanoparticle electrocatalytical action on electrodeposition of nickel and the chemical combination state between nanoparticles and matrix metal in composite coating. The electrochemical behavior, from common and composite brush electroplating solution, is investigated by cyclic voltammetry. The interaction between nanoparticles and matrix metal nickel is researched by X-Ray Photoelectron Spectrometry (XPS). The microstructure and morphology of coating are observed with Transmission Electron Microscope (TEM) and Scanning Electron Microscope (SEM). The results show that nanoparticles not only can obviously induce the increasing of the current efficiency and decreasing of overpotential, but also can distinctly refine the metal crystal grains of composite coating. The experimental results demonstrate that nanoparticles take part in the electrode reaction and can evidently catalyze nickel electrodeposition. Part of the unsaturated oxygen atoms on nanoparticles surface can combine with some of the absorbed nickel atoms and form nickel-oxygen chemical bonds. There is chemical binding interaction at the interface between nanoparticles’ surface and matrix metal nickel.

Wei-Yi Tu

Papers

Study of tribological characteristics and wear mechanism of nano-particle strengthened nickel-based composite coatings under abrasive contaminant lubrication

Electrodepositing nickel silica nano-composites coatings

Electrocatalytic action of nano-SiO2 with electrodeposited nickel matrix

Chemical and electrocatalytical interaction: influence of non-electroactive ceramic nanoparticles on nickel electrodeposition and composite coating