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The ability to produce a uniform composition, high corrosion resistance with a hard coating layer during the electroless coating techniques are mainly based on the plating bath composition. The complexing agent is one of the most important components that control the coating layer properties. This paper aims to investigate the effect of the glycine as a complex agent on the surface and corrosion properties of Ni-P and Ni-P/Al₂O₃ electroless coating.

In this study, the effect of glycine as a complexing agent on the final surface and corrosion properties of the Ni-P and Ni-P/Al₂O₃ coatings has been investigated. The surface morphology and composition of the coated samples were investigated by scanning electron microscope (SEM) imaging and energy dispersive x-ray spectroscopy (EDS) analysis. Linear polarization scan and electrochemical impedance spectroscopy techniques were used to investigate the corrosion properties of the coating layer.

The results clarify that, glycine has a remarkable effect on the porosity content of Ni-P and Ni-P/Al₂O₃. It was found that increasing of glycine concentration results in higher porosity content in the coating layers. Also, the porosity in the coating layers minimizes the protectability of the coating against corrosion. The results also show that adding nano-alumina (Al₂O₃) to the coating path has improved the corrosion properties by decreasing the porosity in the coating layer. The scanning electron microscope (SEM) images showed that the concentration of glycine affects the content and distribution of alumina nanoparticles embedded in the coating layer. Also, it was observed that using a high concentration of glycine (0.4 M glycine), the alumina tends to agglomerate and the final alumina content in the coating was decreased.

The present study reveals that the quality of the final coating plays a major role in the corrosion performance of the steel substrate. The coating quality can by improve remarkably by optimization of the complexing agent used in the plating bath, to minimize the porosity involve in the coating layer.

The purpose of this paper is to investigate the interfacial conductivity and corrosion resistance of the Ni–P/Ti₄O₇ composite coating that is deposited on a carbon steel substrate as bipolar plates for proton exchange membrane fuel cells.

The Ni–P/Ti₄O₇ coating was prepared by electroless plating. Scanning electron microscopy, white light interference, energy dispersive spectrometry and X-ray diffraction were used, respectively, to study the surface morphology, chemical composition and phase composition of coated samples. Electrochemical impedance spectroscopy, potentiodynamic and potentiostatic polarization were used to test the electrochemical performance and corrosion behavior. The interfacial contact resistance (ICR) was measured via the standard method.

The surface of the Ni–P/Ti₄O₇ coating is complete and dense and without obvious defects. The electrochemical test results show that the Ni–P/Ti₄O₇ coating provides better corrosion resistance than the Ni–P coating and substrate. Compared with the Ni–P coating, the ICR of the Ni–P/Ti₄O₇ coating is lower by about 82.7%. This is because the coating has more conductive contact points. The more exciting thing is that the ICR of the Ni–P/Ti₄O₇ coating only increases to 12.38 mΩ·cm² after 5 h of polarization.

This paper provides a method for achieving surface modification of metal bipolar plates. Introducing Ti₄O₇ particles in the Ni–P layer reduces the contact resistance before and after polarization while ensuring good corrosion resistance.

The purpose of this paper is to investigate the deposition of uniform, adherent and crack‐free Ni‐P thin films on carbon fibres using the electroless deposition technique.

Before applying the electroless process, the carbon fibre surfaces must be subjected to several treatment processes to remove the organic binder, etching and surface metallization. The surface morphology of the Ni‐P coatings was assessed using a scanning electron microscope (SEM). The chemical compositions of Ni‐P layers were identified by energy dispersive X‐ray analysis (EDS). The bond strength of the coated layer was determined by measuring the electrical resistance at the fibre/coating interface. The magnetic properties of the fibres were estimated using a hysteresis diagram. The tensile performance of single fibres coated by Ni‐P has been investigated with respect to coating thickness.

Pre‐treatment processes are used to improve the adhesion of Ni‐P layers and to obtain homogeneous coatings. The influence of plating parameters (temperature, pH and time) on the coating thickness of the Ni‐P layer was investigated. It was found that the coating thickness increased as the pH value, plating time and the temperature of the bath increased. The results revealed that a complete and uniform Ni‐P coating on fibre could be obtained at optimum conditions 85°C, pH 6, for 60 min, and the results indicated that the P content in the electroless deposit is approximately 3.4 wt%. The tensile strength values are improved significantly after coating and increased by 3‐5 times with increasing of coating thickness from 0.3 to 2 μm.

The results presented in this work are an insight into understanding of the deposition and adherence of Ni‐P thin films on carbon fibre using the electroless technique and behaviour of the coated fibre.

The purpose of this paper is to evaluate the corrosion resistance of the electroless Ni‐P coatings in two aggressive media 3.5 wt.% NaCl and Synthetic industrial waste water. Also to study the effect of Phosphorous content in the electroless Ni‐P deposits on its surface nature, morphology and corrosion resistance.

The corrosion behavior of electroless Ni‐P coatings generated on mild steel coupons from an acidic and an alkaline baths and their anti‐corrosion performance of was compared systematically in 3.5 wt.% of NaCl solution and also in synthetic industrial waste water. Microstructure and surface composition of coatings were analyzed using X‐ray diffraction, scanning electron microscopy and energy dispersive spectroscopy techniques, respectively. The Ni‐P coated mild steel specimens were subjected to corrosion and the rate of corrosion was studied by chemical and electrochemical methods. The linear sweep voltammetry, Tafel and electrochemical impedance spectroscopy were employed to obtain corrosion data.

The electroless Ni‐P coatings with higher P content possess homogeneous, uniform and amorphous surface nature and exhibited higher corrosion resistance in the aggressive corrosive media chosen.

This paper provides corrosion behavior of electroless Ni‐P coatings in 3.5 wt.% NaCl and synthetic industrial waste water, and establishes the importance of phosphorous content on nature and properties of the coatings.

This paper aims to investigate the structural, corrosion and the study of tribocorrosion features of the AA7075 aluminum alloy with and without the application of electroless Ni-P/Ni-B duplex coating with a thickness of approximately 40 microns.

Surface characterization of the samples was made by structural surveys (light optic microscope, scanning electron microscopic examinations and X-ray diffraction analyses), hardness measurements, corrosion and tribocorrosion tests.

Results of the experiments showed that upper Ni-B coating deposited on the surface of first Ni-P layer by duplex treatment caused remarkable increment in the hardness, corrosion resistance and tribocorrosion performance as compared to the AA7075 aluminum alloy.

This study can be a practical reference and offers insight into the effects of duplex treating on the increase of hardness, corrosion and tribocorrosion performance.

This paper aims to report a study of the influence of tungsten carbide (WC) nanoparticles on corrosion resistance properties of electroless nickel–phosphorus (Ni–P) coatings in NaCl solution.

The morphology of Ni–P–WC nanocomposite coatings was observed by scanning electron microscopy (SEM). The anodic polarization curves, electrochemical impedance spectra (EIS) and weight loss measurements were used to study the corrosion resistance properties of Ni–P–WC nanocomposite coatings in NaCl solution.

The WC nanoparticles content in the coatings increased with the increase of its concentration in the bath, and the WC nanoparticles are uniformly distributed in Ni–P alloy matrix. The results showed that the incorporation of WC nanoparticles elevated the corrosion resistance properties of Ni–P alloy matrix.

This study shows that the corrosion resistance was improved by the addition of WC nanoparticles to the Ni–P alloy matrix.

Electrodeposited Ni‐P composite coatings incorporating a variety of inorganic particles were obtained from Watt’s nickel bath containing sodium hypophosphite. The mechanism of co‐deposition of various particles (SiC, Al₂O₃, quartz and sand) was studied in view of the electro‐kinetic charge characterizing the solid particles. Means to improve the mobility of the particles in the plating solution were investigated using sodium oleate as surface active agent. The purpose was to increase particle content in the coating to attain high hardness values. Special attention was given to the deposition process using SiC particles. The surface morphology, hardness and wear resistance of the composite coatings were determined. Hardness values were maximized by simple heat treatment in air atmosphere which led to the precipitation of the hard Ni₃P phase. Sound, coherent and high wear resistance coatings could be produced.

Metallic finishing of materials, unlike non‐metallic finishing, comprises various popular surface modification processes, e.g. electroplating, conversion coating, anodizing, metal spraying, hot dip coating and also diffusion coatings. Diffusion coatings on metallic substrates are well known for their better abrasion resistance and adhesion to the substrate. Resistance to corrosion may also be incorporated on these surfaces by the addition of appropriate dopant elements like Cr, Ni and Al. However, these diffusion alloy‐layers are more sought after for functional properties than their aesthetic look. It appears that the concept of functional metal finishing is gaining ground for its longer service‐life and better performance. Discusses some of these aspects of diffusion alloy coatings on mild steel substrate and analyses their comparative merits and demerits. In this connection, three distinctly different types of barrier layers, namely, hard diffusion alloy layer, e.g. chromiding, Ni‐Cr diffusion coatings and soft‐diffusion layer, e.g. Pb‐Cd, Zn‐Sn barriers and those in between, e.g. hot dip zinc‐alloy coated barrier layers, have been highlighted for their corrosion resistance properties.

This paper aims to coat ternary composite NiBP-graphite films by Dynamic Chemical Plating “DCP” technique with a growth rate of at least 5 μm/h, which makes this technique a worthy candidate for production of composite films. Electroless nickel plating method can be used to deposit nickel–phosphorous and nickel–boron coatings on metals or plastic surface. However, restrictions such as toxicity, short lifetime of the plating-bath and limited plating rate have limited applications of conventional electroless processes.

DCP is an alternative for producing metallic deposits on non-conductive materials and can be considered as a modified electroless coating process. Using a double-nozzle gun, two different solutions containing the precursors are sprayed simultaneously and separately onto the surface. With this technique, NiBP-graphite films are fabricated and their corrosion and tribological properties are investigated.

With a film thickness of 2 μm, tribological analysis confirms that these coatings have favorable anti-friction and anti-wear properties. Corrosion resistance of NiBP-graphite composite films was investigated, and it was found that graphite incorporation significantly enhances corrosion resistance of NiBP films.

DCP is faster and simpler to perform compared to other electroless deposition techniques. Using a double-nozzle gun, metal salt solution and reducing agents are sprayed to the surface, forming a deposit. Previously, coatings such as Cu, Cu-graphite, Cu-PTFE, Ni-B-TiO2, Ni-P, Ni-B-P and Ni-B-Zn with favorable compactness and adherence by DCP were reported. In this paper, the authors report the application of the DCP technique for depositing NiBP-PTFE nanocomposite films.

The purpose of this paper is to elucidate the tribology behavior of polytetrafluoroethylene (PTFE) incorporated with three types of nickel–phosphorus (Ni-P) particles (i.e. low phosphorus [LP], medium phosphorus [MP] and high phosphorus [HP]) under dry sliding condition.

Ni-HP, Ni-MP and Ni-LP particles fabricated via an electroless plating process were incorporated into PTFE matrix with different additions to prepare Ni-P/PTFE composites (Ni-LP/PTFE, Ni-MP/PTFE and Ni-HP/PTFE). The tribology tests for these samples were carried out on a reciprocating ball-on-disc tribometer. The thermal stabilities, mechanical and tribological properties, morphologies and components of aforesaid Ni-P/PTFE composites were analyzed.

The marvelous effect of Ni-P incorporation on the simultaneous reduction in friction and wear of PTFE was corroborated.

Compared with that of pristine PTFE sample, the reduction on friction with a value of 27% and the reduction in wear about 94% for Ni-HP/PTFE composite is validated, which is probably related to the increased crystallinity and hardness due to the presence of Ni-P particles.