Formation and characterization of borohydride reduced electroless nickel deposits
TL;DR: In this article, the formation of electroless Ni-B deposits and evaluation of their characteristic properties were studied. And the corrosion resistance of Ni-b deposits, in 3.5% sodium chloride solution, both in as-plated and heat-treated (450°C/1 h) conditions, was also evaluated by potentiostatic polarization and electrochemical impedance studies.
About: This article is published in Journal of Alloys and Compounds.The article was published on 2004-02-25. It has received 136 citations till now. The article focuses on the topics: Electroless nickel & Nickel boride.
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TL;DR: In this article, an electroless Ni-B-Tl coating was used with the aim of increasing the surface hardness of stainless steels, and the results showed that the hardness of the coating was increased due to the formation of Ni2B and Ni3B phases during heat treatment.
Abstract: Despite having some useful properties, stainless steels suffer from lack of suitable surface hardness. In this research electroless Ni–B–Tl coating was used with the aim to increase their surface hardness. The effects of nickel chloride, sodium borohydride, thallium nitrate and ethylenediamine on chemical composition of coating were studied. To achieve an increase in hardness, the effects of heat treatment on the hardness of the deposited layer at various temperatures were also studied. The results showed that the deposition rate and surface hardness of the deposited layer are affected by the variation in concentration of bath components. The microstructure of the electroless Ni–B–Tl coating consists of nickel and super saturated solid solutions. It was also found that the hardness of the coating was increased due to the formation of Ni2B and Ni3B phases during heat treatment.
10 citations
TL;DR: In this paper, a Ni3P nano-scale layer on B4C nanoparticles via simple electroless plating in an acidic bath was investigated, and the results confirmed deposition of a Ni 3P layer with the average thickness of about 25 nm on b4c nanoparticles.
Abstract: In this study, deposition of a Ni3P nano-scale layer on B4C nanoparticles via simple electroless plating in an acidic bath was investigated. B4C nanoparticles were produced by mechanical milling with the average size of about 95 nm. Electroless nickel plating was carried out at temperature and pH of 85°C and 5.5, respectively. The uncoated and composite powders were characterized by transition electron microscope and the phases present were revealed by X-ray diffraction. Also, nickel and phosphorous contents of the coating were measured by inductively coupled plasma analysis. The results confirmed deposition of a Ni3P layer with the average thickness of about 25 nm on B4C nanoparticles.
9 citations
Cites background from "Formation and characterization of b..."
...These unique properties include corrosion and wear resistance (Sankara Narayanan and Seshadri 2004), hardness, lubricity, M. Hajizamani A. Alizadeh (&) N. Ehsani Faculty of Materials and Manufacturing Processes, MUT, PO Box 15875-1774, Tehran, Iran e-mail: al.alizad53@gmail.com uniformity of…...
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TL;DR: In this paper, the effect of nanoparticles on morphology and structure was investigated by FE-SEM, XRD and AFM tests, which revealed that the presence of silica nanoparticles results in an increase in the microhardness and corrosion resistance.
Abstract: The beneficial role of silica nanoparticles addition as reinforcing agent on the various properties of the novel developed Ni-Ba-B coating was highlighted. Barium was considered as third element to act as an inhibiting alloying element for anodic passivation purposes. The ternary Ni-Ba-B coatings in three different concentrations of silica nanoparticles (0.5, 1.0 and 2.0 g/L) were coated on St 37 steel substrate in the presence of sodium dodecyl sulfate (SDS). The effect of nanoparticles on morphology and structure was investigated by FE-SEM, XRD and AFM tests. The nodularity and surface roughness of the coating increased by the presence of SiO2 nanoparticles in the electroless bath. The nanocomposite coating has amorphous and crystalline phases and its XRD peak at 44.50 is slightly sharper than the composite coating. DSC thermogram showed two exothermic peaks demonstrating its phase transformations. The WCA value of coating was confirmed its hydrophilicity property. Results also confirmed that the existence of silica nanoparticles results in an increase in the microhardness and corrosion resistance which may be attributed to the distribution of silica nanoparticles into Ni-Ba-B matrix.
9 citations
TL;DR: In this article, a citrate stabilised electroless bath was developed and the process parameters (concentrations of nickel, reducing agent, and stabiliser) were optimised to achieve the maximum energy efficiency.
Abstract: In this work, a novel citrate stabilised electroless bath was developed and the process parameters (concentrations of nickel, reducing agent, and stabiliser) were optimised to achieve the maximum h...
9 citations
TL;DR: Ni-B alloy films containing amorphous boron particles were fabricated by electrodeposition and were subsequently subjected to heat-treatment as discussed by the authors, and their compositions and microstructures were characterized, and their hardness was evaluated.
Abstract: Ni-B alloy films containing amorphous boron particles (referred to as "Ni-B alloy composite films") were fabricated by electrodeposition and were subsequently subjected to heat-treatment. Their compositions and microstructures were characterized, and their hardness was evaluated. The content of boron particles in the alloy composite films increased with boron particle concentration in the plating baths. In addition, the total boron content in the films increased with decreasing current density, reaching a maximum value of 34.3 atom %. The boron particles were homogeneously distributed in these alloy composite films and exhibited no cohesion. Heat-treatment of the alloy composite films consisting of a Ni-B alloy matrix and the boron particles led to a phase conversion from an inhomogeneous amorphous phase to stable homogeneous crystalline phases, which were similar to those in the Ni-B binary alloy phase diagram. The hardness of the Ni-B alloy 34.3 atom % B composite film was higher than that of a Ni-B alloy film both before and after heat-treatment.
8 citations
References
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Book•
01 Jan 1990
TL;DR: The Electroless Plating: Fundamentals and Applications (ESPA) as discussed by the authors is a comprehensive text that covers both fundamental and applied aspects of electroless deposition, and was first introduced at SUR/FIN '91.
Abstract: Many texts have been written on surface finishing over the years that deal with electroless deposition as a sidelight. Through the talents and efforts of Glenn Mallory and Juan Hajdu, a comprehensive text, entitled Electroless Plating: Fundamentals and Applications, is available through AESF Headquarters. The editors have combined the efforts of 27 contributing authors to produce a wide-ranging text that covers both fundamental and applied aspects of the subject. Published by the AESF, the book was first introduced at SUR/FIN ‘91—Toronto.
963 citations
Patent•
23 Sep 1968
TL;DR: HIGH STABILITY, AUTOCATALYTIC ELECTROLESS NICKEL PLATING BATH COMPRISING an AQUEOUS SOLUTION CONTAINing about 0.08-016 MOLE/LITER NICKels IONS, about 019-0.38 MOLE / LITER HYPOPHOSPHITE IONS and ESSENTIALLY about 035-3.14 MOLE or Liter CITRATE IONS as discussed by the authors.
Abstract: HIGH STABILITY, AUTOCATALYTIC ELECTROLESS NICKEL PLATING BATH COMPRISING AN AQUEOUS SOLUTION CONTAINING ABOUT 0.08-016 MOLE/LITER NICKEL IONS, ABOUT 0.19-0.38 MOLE/ LITER HYPOPHOSPHITE IONS, AND ESSENTIALLY ABOUT 0.35-3.68 MOLE/LITER AMMONIUM IONS, ABOUT 0.0.-1.07 MOLE/LITER ACETATE ION AND ABOUT 0.007-0.14 MOLE/LITER CITRATE IONS, THE SOLUTION HAVING A PH IN THE RANGE OF ABOUT 7.0 TO ABOUT 9.5 THE AMMONIUM IONS COMPLEX PALLADOUS IONS INTRODUCED INTO THE PLATING BATH BY "DRAG OUT" FROM THE ACTIVATOR SOLUTION TO FORM A SOLUBLE AMMONIUM-PALLADIUM COMPLEX, WHICH INHIBITS REDUCTION OF PALLADOUS ION TO ZERO VALENT CATALYTIC PALLADIUM BY THE HYPOPHOSPHITE OF THE BATH. BY THE REMOVAL OF POTENTIAL CATALYST SITES FROM THE BATH OR BY RENDERING THE POTENTIAL SITES RELATIVELY CATALYTICALLY INACTIVE, RANDOM DEPOSITION OF THE NICKEL AND PREMATURE LOSS OF THE BATH IS AVOIDED.
154 citations
TL;DR: In this paper, the same fundamental reaction is occurring on all the coatings of the present study but over a different effective area in each case, which can be attributed to the decrease in the effective metallic area prone to corrosion.
Abstract: 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>Ni-P-TiO2.
119 citations
TL;DR: In this paper, the effect of phosphorus on the corrosion behavior of electroless nickel-plated mild steel in deaerated 40 w/o NaOH solution was examined using potentiodynamic polarization curves and electrochemical impedance spectroscopy (EIS) techniques.
Abstract: Electroless Ni-P deposits with phosphorus content ranging from 4.8 to 12.8 weight percent (w/o) were examined using potentiodynamic polarization curves and electrochemical impedance spectroscopy (EIS) techniques to characterize the effect of phosphorus on the corrosion behavior of electroless nickel-plated mild steel in deaerated 40 w/o NaOH solution. Anodic polarization of the electroless Ni-P alloys in caustic NaOH solution shows that the passive current density decreases with increasing phosphorus content in the deposits. At an applied potential of -1.2 V vs. saturated calomel electrode (V SCE ) (close to their E corr ), EIS data indicate that the R ct for Ni-P alloys in NaOH solution increases with increasing phosphorus content. X-ray photoelectron spectroscopy (XPS) results suggest that the primary constituent formed on the Ni-P surface after EIS measurement in 40 w/o NaOH solution at an applied potential of -0.4 V SCE (in the passive region) is Ni(OH) 2 , which is responsible for the passivity of the Ni-P alloys. The polarization resistance of Ni-P alloys in NaOH solution at -0.4 V SCE also increases with increasing phosphorus content
111 citations