Nickel and nickel-phosphorous matrix composite electrocoatings

Spyrellis, N.; Pavlatou, Evangelia A.; Spanou, S.; Zoikis-Karathanasis, Alexandros

doi:10.1016/s1003-6326(08)60353-2

Cited by 28 publications

(12 citation statements)

References 11 publications

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“…Higher current density increased the H 2 evolution and therefore reduced the CE. It has also been reported that SiC particles can adsorb protons and consequently, result in increased hydrogen evolution [29,38,39]. In this study, CE varies in a wide interval, and neither addition of SiC nor increasing current density decreased the CE values.…”

Section: Methodsmentioning

confidence: 47%

The Effects of Additives, Particles Load and Current Density on Codeposition of SiC Particles in NiP Nanocomposite Coatings

Ahmadkhaniha

Zanella

2019

Coatings

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In this study, electrodeposition of NiP composite coatings with the addition of SiC 100 nm was carried out on low carbon steel studying the effect of additives (sodium dodecyl sulfate, saccharin), particles load (10 or 20 g/L) and current density (1, 2 and 4 A/dm 2 ). As a benchmark, coatings from an additive-free bath were also deposited, despite additives being essential for a good quality of the coatings. The coating's morphology and composition were evaluated by scanning electron microscope (SEM) equipped with energy dispersive spectroscopy (EDS). It was shown that by addition of sodium dodecyl sulfate (SDS), pure NiP coating with a higher P content was achieved, and their morphology changed to nodular. SDS also reduced the codeposited fraction of SiC particles, while saccharin increased it. SiC loading and current density had less impact respect to the additives on codeposition of SiC particles. Finally, the microhardness of NiP coatings did not increase linearly by codeposition of SiC particles.Meanwhile, the amount and distribution of particles are related to electrodeposition parameters including particle characteristics (particle shape, size, concentration and surface charge), electrolyte composition (additives, surfactant type and concentration), pH and applied current (direct or pulsed current and current density) [17][18][19][20][21]. Several studies have reported the effect of process parameters on the amount of codeposited particles in the metal matrix [18][19][20][21][22][23][24][25]. However, a low number of particles are usually codeposited in the case of nanoparticles, and they tend to agglomerate, which results in the poor mechanical behaviour of the coatings. Hence, increasing the amount of codeposition as well as improving the particle distribution in the matrix are the crucial issues that require further investigation.It is well known that introducing additives to the electrolyte affects the properties and appearance of deposits [20,22,25]. Additives can be categorised based on their application as grain refiners, levelling agents, and wetting agents or surfactants. Saccharin is a common brightening agent in the electrodeposition of nickel, which refines grains, inhibits the hydrogen evolution reaction and reduces the internal stress of the coatings [25][26][27][28]. In previous studies, it was shown that the addition of saccharin significantly improves the cathode current efficiency of the NiP electrodeposition [29]. However, saccharin decreased the SiC codeposition and phosphorus content, compared to deposits obtained from saccharin-free baths [30].Surfactants such as sodium dodecyl sulfate (SDS) are needed in the case of electrodeposition processes where the current efficiency is below 100%. Hydrogen evolution is the common secondary cathodic reaction, and SDS can reduce the residence time of the H 2 bubble on the cathodic surface, and also pitting as well as porosity. Surfactants are beneficial for enhancing the stability and uniformity of the electrolyte by increasing the wettability an...

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Section: Methodsmentioning

confidence: 47%

The Effects of Additives, Particles Load and Current Density on Codeposition of SiC Particles in NiP Nanocomposite Coatings

Ahmadkhaniha

Zanella

2019

Coatings

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“…It should be noticed that in order to obtain a dispersionstrengthening effect, it is crucial to achieve a uniform embedding of non-agglomerated nano-particles in the matrix. It is worth to be mentioned that, according to previous experimental findings by applying HRFE-SEM [25], as well as GDOS [14] techniques the distribution of the TiO 2 nano-particles on the surface and within the thickness has been indicated as uniform, without serious problems of agglomeration. In order to elucidate the hardening mechanism of both direct and pulse plated pure and composite nickel coatings, the microhardness values of deposits exhibiting three different textures ([110], [100], Random) have been plotted as a function of the codeposition percentage and the reciprocal square root of average grain size, while the average grain size was varied within the range 15-500 nm.…”

Section: Correlation Between Structural Characteristics and Microhardmentioning

confidence: 91%

Ni/nano-TiO₂ Composite Electrocoatings: Correlation Between Structural Characteristics Microhardness and Wear Resistance

Spanou

Pavlatou²

2011

Zeitschrift Für Physikalische Chemie

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Electrodeposition / Crystalline Orientation / Microharness / Wear Resistance / Grain SizeNanocomposite coatings were obtained by electrochemical codeposition of TiO 2 nano-particles (mean diameter 21 nm, Degussa P 25 ) with nickel, from an additive-free Watts type bath. Pure Ni and composite Ni-TiO 2 coatings were electrolytically deposited under both direct and pulse current conditions and an extended region of electrolysis conditions (pH, current density, TiO 2 loading in the bath). Pure Ni deposits were produced under the same experimental conditions for comparison. The aim of this study was to correlate the observed structural characteristics of the coatings (crystallographic orientation and grain size of nickel matrix,) and incorporation percentage with the resulting microhardness values and tribological behavior. Overall, the data have demonstrated that when attributing the observed strengthening effect of composites, not only grain refinement and dispersion strengthening mechanisms, but also preferred crystalline orientation should be taken into consideration. The variation of the wear rate is directly associated with the microhardness variations and consequently, governed by the same parameters that determine the synergistic strengthening mechanism proposed. Pure and composite coatings with [110] crystalline orientation exhibited the highest microhardness values and wear resistance.

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“…Thus, different plating parameters such as current density, the composition of the bath and different sizes of the particles have been examined to improve the codeposition rate. [15][16][17][21][22][23][24][25][26][27][28][29][30][31] In this regard, pulse current deposition can be a possible technique to produce composite coatings with an appropriate codeposition rate of ceramic particles. Electrodeposition by pulse current (PC) is a well-known method of depositing metals and alloys, and it can control the properties of the material by modifying their microstructure.…”

Section: Introductionmentioning

confidence: 99%

“…They also observed that pulsed current results in composite deposits with a high codeposition of WC particles in the matrix. 10 Spyrellis et al 27 achieved a higher and better distribution of particles in the matrix in pulse plated Ni and Ni-P coatings than in DC plated ones. Although there has been a variety of research aims and methodologies on NiP coatings, they have been mainly produced by electroless or direct current deposition and less information is available on pulse plating of these coatings.…”

Section: Introductionmentioning

confidence: 99%

Study of the effect of pulse plating parameters on the electrodeposition of NiP and NiP/SiC coatings and their microhardness values

Ahmadkhaniha

Tsongas

Tzetzis

et al. 2021

Transactions of the IMF

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This study is focused on finding optimised conditions for electrodeposition of NiP and NiP/SiC coatings, which enhance the coatings' microhardness. Both the effect of particles and the effect of heat treatment at 400°C for 1 h on the microhardness of the coating were studied. The effects of pulse electrodeposition parameters including duty cycle, frequency, and peak current density on the composition of NiP and NiP/SiC composite coatings were examined, and the results were compared with those from direct current plating. Pulse plating increased the current efficiency of NiP deposition while decreasing the phosphorus content of these coatings in comparison to direct plating, resulting in higher microhardness values. It was also shown that wt.%P in NiP coating depends not only on peak current density but also on bath charge of pulse plating. Pulse plating parameters (duty cycle and frequency) and the low incorporation of SiC particles did not affect microstructure or the microhardness of the coatings, while heat treatment was the main factor that increased microhardness.

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Nickel and nickel-phosphorous matrix composite electrocoatings

Cited by 28 publications

References 11 publications

The Effects of Additives, Particles Load and Current Density on Codeposition of SiC Particles in NiP Nanocomposite Coatings

The Effects of Additives, Particles Load and Current Density on Codeposition of SiC Particles in NiP Nanocomposite Coatings

Ni/nano-TiO₂ Composite Electrocoatings: Correlation Between Structural Characteristics Microhardness and Wear Resistance

Study of the effect of pulse plating parameters on the electrodeposition of NiP and NiP/SiC coatings and their microhardness values

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Nickel and nickel-phosphorous matrix composite electrocoatings

Cited by 28 publications

References 11 publications

The Effects of Additives, Particles Load and Current Density on Codeposition of SiC Particles in NiP Nanocomposite Coatings

The Effects of Additives, Particles Load and Current Density on Codeposition of SiC Particles in NiP Nanocomposite Coatings

Ni/nano-TiO2 Composite Electrocoatings: Correlation Between Structural Characteristics Microhardness and Wear Resistance

Study of the effect of pulse plating parameters on the electrodeposition of NiP and NiP/SiC coatings and their microhardness values

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Ni/nano-TiO₂ Composite Electrocoatings: Correlation Between Structural Characteristics Microhardness and Wear Resistance