This review outlines the development of electroless Ni-P composite coatings. It highlights the method of formation, mechanism of particle incorporation, factors influencing particle incorporation, effect of particle incorporation on the structure, hardness, friction, wear and abrasion resistance, corrosion resistance, high temperature oxidation resistance of electroless Ni-P composite coatings as well as their applications. The improvement in surface properties offered by such composite coatings will have a significant impact on numerous industrial applications and in the future they will secure a more prominent place in the surface engineering of metals and alloys.

Suresh Krishnamoorthy Seshadri

Coatings

Composite materials

Corrosion resistance

Electrodeposition

Friction

Hardness

Nickel compounds

Structure (composition)

Wear of materials

Wear resistance

High temperature oxidation resistance

NICKEL PHOSPHIDE COMPOSITE COATINGS

PARTICLE INCORPORATION

Electroless plating

IIT Madras is a public technical and research university located in Chennai, Tamil Nadu. Founded in 1959, it is recognised as an Institute of National Importance.

IIT Madras has been ranked as the top engineering institute in India for four years in a row by the National Institutional Ranking Framework of the MHRD

It currently offers undergraduate, postgraduate and research degrees across 16 disciplines in Engineering, Sciences, Humanities and Management. About 596 faculty belonging to science and engineering departments and centres of the Institute are engaged in teaching, research and industrial consultancy.

IIT Madras

Electroless Ni-P composite coatings

Journal of Applied Electrochemistry

This paper investigates the effects of surfactants on microhardness, scratch, wear and friction behaviour of the Ni-P-nano-TiO2 composite coatings. Nano TiO2 particles were co-deposited with electroless Ni-P coating on low carbon steel substrates in the presence of anionic and cationic surfactants-sodium dodecyl sulphate (SDS) and dodecyl trimethyl ammonium bromide (DTAB) respectively. Results revealed that at an optimum concentration of the surfactants, the coatings obtained a smoother surface, low frictional coefficient, enhanced microhardness and high wear resistance. The findings of scratch test showed that the composite coatings with surfactants exhibited the ability to withstand higher critical load and lower penetration depth. This can be ascribed to the reinforcing action of co-deposited TiO2 nanoparticles in the composite coatings. The cationic surfactant DTAB contributed to the increase in weight percentage of TiO2 in the Ni-P matrix considerably. At critical micelle concentration (CMC) value of the DTAB surfactant, the coatings had the highest weight percent of incorporated TiO2 and showed a better homogenous distribution. © 2015 Elsevier B.V.

Wear

Wear and scratch behaviour of electroless Ni-P-nano-TiO2: Effect of surfactants

The development of metal deposition processes based on electroless nickel, alloy and composite coatings on various surfaces has witnessed a surge in interest among researchers, with many recent applications made possible from many excellent properties. In recent years, these coatings have shown promising corrosion and wear resistance properties and large number of newer developments became most important from macro to nano level applications. After a brief review of the fundamental aspects underlying the coating processes, this paper discusses in detail about different electroless nickel alloy, composite, nano plating, bath techniques, preparation, characterization, new depositing mechanism and their recent applications, including brief notes on difficult substrate and waste treatment for green environment. Emphasis will be onto their recent progress, which will be discussed in detail and critically reviewed. © 2013 Elsevier B.V. All rights reserved.

Fulltext

Journal of Alloys and Compounds

Electroless nickel, alloy, composite and nano coatings - A critical review

Deposition of electroless (EL) Ni-B-Si 3N 4 composite coating and its characteristic properties are addressed.Hydrogen evolution limits the level of incorporation of Si 3N 4 particles in the EL Ni-B matrix to 2 wt%. Incorporation Si 3N 4 particles increased the surface roughness of the matrix but did not influence its structure. The microhardness of EL Ni-B-Si 3N 4 composite coating in its as-plated condition is 632 ± 17 HV0. 1. Heat treatment at 350 and 450°C for 1 h increased its hardness. Adhesive wear is the predominant wear mechanism of EL Ni-B-Si 3N 4 composite coating. Its corrosion protective ability did not differ much with its plain counterpart. © 2012 Copyright Taylor and Francis Group, LLC.

Synthesis and Reactivity in Inorganic, Metal-Organic and Nano-Metal Chemistry

Electroless Ni-B-Si 3N 4 composite coating: Deposition and evaluation of its characteristic properties

Surface degradation processes such as wear, oxidation, corrosion and fatigue cause failure of many engineering components under varied circumstances. Among the various surface engineering processes, phosphate conversion coatings and, electro- and electroless plating processes have received widespread acceptance following their less complex processing sequence and cost-effectiveness. The present review addresses the recent developments in the areas of phosphate conversion coatings, electro deposition and electroless deposition. © 2011, by Walter de Gruyter GmbH & Co. All rights reserved.

Corrosion Reviews

Recent advances in surface treatment and electrodeposition

The wear resistance of electrodeposited (ED) Ni-B and Ni-B-Si 3N4 composite coatings is compared. The effect of incorporation of Si3N4 particles in the ED Ni-B matrix on the surface morphology, structural characteristics and microhardness has been evaluated to correlate the wear resistance. The wear mechanism of ED Ni-B and Ni-B-Si3N4 composite coatings appears to be similar; both involve intensive plastic deformation of the coating due to the ploughing action of the hard counter disc. However, the extent of wear damage is relatively small for ED Ni-B-Si3N4 composite coatings. © 2008 Springer Science+Business Media, LLC.

Journal of Materials Science

Wear resistance of electrodeposited Ni-B and Ni-B-Si3N 4 composite coatings

Electroless Ni-P composite coatings have gained a good deal of popularity and acceptance in recent years as they provide considerable improvement of desirable qualities such as hardness, wear, abrasion resistance, etc. The disagreement among researchers on the corrosion behaviour of these coatings warrants a thorough investigation. Among the various techniques available for the determination of corrosion resistance, electrochemical impedance spectroscopy (EIS) is considered to be superior as it provides not only an assessment of the corrosion resistance of different deposits but also enables the mechanistic pathway by which the deposits become corroded to be determined. The present investigation focuses on the evaluation of the corrosion resistance of electroless Ni-P and Ni-P-Si3N4, Ni-P-CeO2 and Ni-P-TiO2 composite coatings produced using an acidic hypophosphite-reduced electroless nickel bath, using EIS. The study makes evident that the same fundamental reaction is occurring on all the coatings of the present study but over a different effective area in each case. The charge transfer resistance of electroless Ni-P and Ni-P composite deposits are in the range 32,253-90,700 Ω cm2, whereas the capacitances of these coatings are in the range 11-17 μF/cm2. The improved corrosion resistance obtained for electroless Ni-P and Ni-P composite coatings is due to the enrichment of phosphorus on the electrode surface, which enables the preferential hydrolysis of phosphorus over that of nickel. The better corrosion resistance obtained for electroless Ni-P composite coatings can be ascribed to the decrease in the effective metallic area prone to corrosion. Among the three electroless Ni-P composite coatings, the corrosion resistance is in the following order: Ni-P-CeO2 = Ni-P-Si3N4 &gt; Ni-P-TiO2.

Journal of Solid State Electrochemistry

Evaluation of the corrosion resistance of electroless Ni-P and Ni-P composite coatings by electrochemical impedance spectroscopy

The present work pertains to the study of electroless Ni-P and Ni-P-Si3N4 composite coatings. The deposits are obtained from a proprietary high phosphorus electroless nickel plating bath, comprising nickel sulphate, sodium hypophosphite, complexing agents and stabilizers. The maximum weight percent of Si3N4 incorporated in the electroless deposits is obtained at a concentration of 10 g/l in the bath. The electroless Ni-P deposits have 0%, 2.01%, 5.81% and 8.10% of Si3N4, respectively, obtained from baths containing 0, 2, 5 and 10 g/l of Si3N4, are characterized by optical microscopy, XRD and TEM. Hardness is found to increase with the incorporation of Si3N4 at all heat treatment temperatures studied. Also hardness increases with an increase in weight percent of Si3N4 incorporated in the deposit. The analyses of the composite coatings by XRD and TEM reveal that the inclusion of Si3N4 particles does not change the amorphous nature of the Ni-P matrix.

Transactions of the Institute of Metal Finishing

Preparation and characterization of electroless Ni-P and Ni-P-Si3N4 composite coatings

Journal of Materials Science Letters

Synthesis and corrosion behavior of electroless Ni-P-Si3N4 composite coatings

Carbon

Tribological application of carbon nanotubes in a metal-based composite coating and composites

Materials Letters

Tribological properties of Ni–P-multi-walled carbon nanotubes electroless composite coating

Journal	Journal of Applied Electrochemistry
ISSN	0021891X
Open Access	No