Influence of the particle size on the mechanical and electrochemical behaviour of micro- and nano-nickel matrix composite coatings (original) (raw)
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Journal of Alloys and Compounds, 2014
ABSTRACT Electrodeposition process is a very promising method for producing metal matrix composites reinforced with ceramic particles. In this method insoluble particles suspended in an electrolytic bath are embedded in a growing metal layer. This paper is focused on the investigations of the nickel matrix nanocomposite coatings with hard alpha-Al2O3 nano-particles, electrochemically deposited from modified Watts-type baths on steel substrates. The influence of various current densities on the microstructure, residual stresses, texture, hardness and corrosion resistance of the deposited nickel/alumina coatings was investigated. The surface morphology, cross sections of the coatings and distribution of the ceramic particles in the metal matrix were examined by scanning electron microscopy. The phase composition, residual stresses and preferred grain orientation of the coatings were characterized using X-ray diffraction techniques. The coating morphology revealed that alpha-Al2O3 particles show a distinct tendency to form agglomerates, approximately uniformly distributed into the nickel matrix.
Electrodeposition and Mechanical Characterization of Ni/SiC Composite Coatings
Journal of Nano- and Electronic Physics, 2019
The need to improve coatings for better properties leads to the development of composite electrolytic deposition, by adding insoluble solid particles to the electrolyte. These coatings typically contain ceramic particles in an electrodeposited matrix such as nickel. The aim of this work is to obtain an electrolytic nickel matrix (binder) with and without adding silicon carbide SiC microparticles (mean diameter 0.8 m) which have a high hardness and a good chemical stability. The structural (Ni-SiC) composite and pure nickel coatings were prepared by electroplating deposition on steel in a Watts bath of electroplating chloride. The surface morphology, microstructure, and composition were studied by atomic force microscopy (AFM), nanoindentation, scanning electron microscopy (SEM) and X-ray diffractometer. The characterizations of the deposited layers are carried out in 3.5 % NaCl solution. The weight loss and the polarization results highlighted that the corrosion rate decreases with the increase of SiC concentration up to 15 gl-1. This decrease is probably due to the presence of SiC particles leading to improved corrosion resistance. These properties are mainly due to the homogeneous distribution of the constituents SiC as determined by AFM technique and the possibilities of combining the characteristics of base metals and their coatings. Moreover, the incorporation of the microparticles had a significant impact on the microhardness of the composite deposits Ni-SiC.
Applied Surface Science, 2012
In the present work, a nickel sulfate bath containing SiC submicron particles between 100 and 1000 nm was used as the plating electrolyte. The aim of this work is to obtain Ni-SiC metal matrix composites (MMCs) reinforced with submicron particles on steel surfaces with high hardness and wear resistance for using in anti-wear applications such as dies, tools and working parts for automobiles and vehicles. The influence of the SiC content in the electrolyte on particle distribution, microhardness and wear resistance of nano-composite coatings was studied. During the electroplating process, the proper stirring speed was also determined for sub-micron SiC deposition with Ni matrix. The Ni films were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD) analysis. The depositions were controlled to obtain a specific thickness (between 50 and 200 m) and volume fraction of the particles in the matrix (between 0.02 and 0.10). The hardness of the coatings was measured to be 280-571 HV depending on the particle volume in the Ni matrix. The tribological behaviors of the electrodeposited SiC nanocomposite coatings sliding against an M50 steel ball (Ø 10 mm) were examined on a tribometer. All the friction and wear tests were performed without lubrication at room temperature and in the ambient air (with a relative humidity of 55-65%). The results showed that the wear resistance of the nanocomposites was approximately 2-2.2 times more than those of unreinforced Ni.
Interface behaviour in nickel composite coatings with nano-particles of oxidic ceramic
Electrochimica Acta, 2003
Advances in micro-technology demand that new functional materials be developed so that the technical properties of microdevices can be improved at reasonable cost. The co-deposition of nanoscaled particles during an electroplating process has been shown to bring such an improvement. This work focuses on particles of oxidic ceramics, in this case those of Al 2 O 3 and TiO 2 . The diameters of the primary particles ranges from 10 to 30 nm, electrodeposited by means of a conventional Watts nickel electrolyte. A series of nickel nano-ceramic composites were produced, with co-deposition of particles as a single primary particle in the nanometre range at one end of the scale and as agglomerates up to a size of a micrometer at the other. The influence of the presence of particles on crystallisation behaviour, residual stress and texture of the deposited nickel coatings was examined by X-ray diffraction (XRD). There is a report on the interfaces between the nickel grains and the oxidic ceramic particles, investigated using transmission electron microscopy (TEM). A decreasing corrosion stability indicates an attack along the interface nickel/particles.
Electrodeposited Ni-B/SiC micro- and nano-composite coatings: A comparative study
Journal of Alloys and Compounds, 2019
Ni-B/SiC micro-and nano-composite coatings were electrodeposited in a modified watts bath containing SiC micro-and nano-particles with the average size of 3 µm and 100 nm, respectively. The chemical composition, SiC content; X SiC (wt.%), morphology, surface roughness, thickness, hardness and corrosion resistance of the deposited coatings were studied as a function of the particle concentration in the deposition bath (C SiC =2, 4, 6, 8 g/L) and deposition current density (i d =0.5, 1, 2 and 3 A/dm 2), using Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS), Inductively Coupled Plasma (ICP), X-Ray Diffraction (XRD), microhardness measurements and potentiodynamic polarization (PP) tastings, respectively. The results indicated that the SiC content and surface roughness (R a) of micro-composite coatings are increased with increasing both the C SiC and i d and reached to the maximum of X SiC =14.8 wt.% and R a =4.58 µm at the C SiC =8 g/L and i d =3 A/dm 2. While the SiC content and roughness of nano-composite coating are initially increased and then decreased with increasing both the C SiC and i d and the maximum of X SiC =9.6 wt.% and R a =2.28 µm were obtained at the C SiC =4 g/L and i d =1 A/dm 2. The thickness of both type of coatings increases almost linearly with i d and micro-composite coatings exhibit greater thickness values. The nano-composites exhibit higher hardness and corrosion resistance than micro-composites despite having lower SiC contents. The maximum hardness and minimum corrosion resistance were 1035 HV and 0.03 µA/cm 2 for micro-and 889 HV and 0.38 µA/cm 2 for nan-composite coatings, respectively.
Journal of Materials Science
This study analysed the influence of the codeposition of SiC particles with different sizes: 50 nm, 500 nm and 5 μm, and the type of bath agitation (stirring or ultrasonic) on the electrocrystallisation of nickel coatings. The composites matrix microstructure was analysed by means of SEM, EBSD and XRD, to evaluate the grain size, crystal orientation, and internal stresses and was benchmarked against pure nickel samples electrodeposited in equivalent conditions. The codeposition of nano- and microsize particles with an approximate content of 0.8 and 4 vol.%, respectively, caused only a minor grain refinement and did not vary the dominant crystal orientation observed in pure Ni. The internal stress was, however, increased by particles codeposition, up to 104 MPa by nanoparticles and 57 MPa by microparticles, compared to the values observed in pure nickel (41 MPa). The higher codeposition rate (11 vol.%) obtained by the addition of submicron-size particles caused a change in the grain...
Electroplated Nickel Composites with Micron- to Nano-Sized Particles
Key Engineering Materials, 2008
Electroplated nickel coatings provide ductility, excellent corrosion resistance and good wear resistance, which qualifies them to meet complex demands of engineering, microtechnology and microelectronics. The co-deposition of particles is a promising alternative to deposit layers with adequate microstructure and properties avoiding the rise of residual stress. The incorporation of the sufficient quantity of particles, monodisperse distribution and downsizing to nanometre scale affect the amount of strengthening by dispersion hardening. To avoid agglomeration in the electroplating bath as well as in the layer is a challenge which has been met by simple Watts nickel electrolyte with a minimum of organic additives and adequate bath agitation comprising sonication, i.e. the exposure of the bath to high-frequency sound waves.
Applied Surface Science, 2007
Metal matrix composites reinforced with nano-sized particles have attracted scientific and technological interest due to the enhanced properties exhibited by these coatings. Ni-SiC composites have gained widespread application for the protection of friction parts in the automobile industry. The influence of variables like SiC content, current density and stirring speed on microhardness of nano-composite coatings has been studied. The improved microhardness was associated with the reduction in crystallite size determined by X-ray diffraction studies. The influence of incorporation of nano-SiC in hardened Ni-Co alloy matrix was also studied. It was observed that for 28wt.%Co content in the matrix the microhardness was higher compared to 70wt.% for a given nano-SiC content.
Electrodeposition and heat treatment of nickel/silicon carbide composites
Surface and Coatings Technology, 2008
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.
2016
The nanocrystalline nickel and nickel-cobalt coatings were electrodeposited on an A60 steel substrate in a modified Watts bath. The observation of the coatings produced by scanning electron microscopy (SEM) showed that the nickel coatings have a granular structure whereas the Ni-Co alloy deposits have a lens-shaped structure with a considerable increase in the grains size of the Ni-Co alloy deposits. Analysis by profilometer confirms these results where we find that the surface roughness of nano-crystalline nickel coatings is less than that of Ni-Co alloy coatings. The results of XRD showed that the nickel coatings having an fcc phase structure while the Ni-Co coatings have a mixed phase structure hcp + fcc. . The study of micro-hardness of the coatings show that this latter follow the Hall Petche effect where nickel deposits which have the small grain size compared to that of the Ni-Co alloy show a higher microhardness to that of Ni-Co coatings. Pin on disk tribometric analysis und...