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 amorphous Ni-P surface was obtained with 73.70% Ni and 11.45% P using electrochemical impedance spectroscopy (EIS) measurements.
42 citations
TL;DR: In this article, a fused porous Ni3B network was synthesized using a modified polyol method using X-ray diffraction, transmission electron microscopy, and electron diffraction.
Abstract: Crystalline Ni3B with a fused porous nanoparticle network has been synthesized directly in solution using a modified polyol method. KBH4 serves both as a reducing agent for Ni2+ and as a boron source, while tetraethylene glycol serves as a solvent capable of achieving reaction temperatures that can crystallize Ni3B. The reaction pathway was studied using X-ray diffraction, transmission electron microscopy, and electron diffraction, and a nucleation−aggregation−smoothing mechanism is proposed. Amorphous Ni−B alloy nanoparticles form first and then aggregate into larger networks, which crystallize and smooth to form porous crystalline Ni3B nanoparticle networks. Structural characterization by X-ray diffraction indicates that the lattice constants for nanocrystalline Ni3B are shifted relative to single-crystal Ni3B, likely because of some carbon incorporation based on X-ray photoelectron spectroscopy data. Magnetic measurements suggest the formation of a small amount of nanocrystalline Ni, which provides fur...
42 citations
TL;DR: In this article, the catalytic hydrogenations of sulfolene to sulfolane over different supported amorphous Ni−B alloy catalysts and Raney nickel catalysts were performed in a batch reactor under pressurized conditions.
Abstract: The catalytic hydrogenations of sulfolene to sulfolane over different supported amorphous Ni−B alloy catalysts and Raney nickel catalysts were performed in a batch reactor under pressurized conditions. The deposition of amorphous Ni−B particles (average Ni−B particle size = 40.5 nm) on MgO was carried out by a silver-catalyzed electroless plating technique. The influence of significant variables, such as the plating temperature and content of potassium borohydride, was investigated in the preparation. The silver and Ni−B loadings in the catalyst were varied as well. The catalysts were characterized by X-ray powder diffraction (XRD), inductively coupled plasma (ICP) spectrometry, high-resolution transmission electron microscopy (HRTEM), scanning electron microscopy (SEM), and N2 physisorption. The load of nickel on MgO increases with the plating temperature, use of potassium borohydride, and loading of silver. The best Ni−B/MgO catalyst showed a remarkably superior catalytic activity to that of the Ni−B/Ti...
41 citations
TL;DR: In this article, the structure and mechanical properties of electroless nickel-boride (Ni-B) thin film coatings on S7 steel substrate were studied in as-plated and annealed samples.
Abstract: Structure and mechanical properties of electroless nickel-boride (Ni–B) thin film coatings on S7 steel substrate were studied in as-plated and annealed samples. The electroless bath does not contain Pb, Cd, or Ta in the stabilizer agents. The mechanical properties of the Ni–B coatings were obtained from nanoindentation measurements. Models by Korsusky and King were used to obtain hardness and elastic modulus, respectively. The structure of the coatings was observed by atomic force and scanning electron microscopy and XRD. Bath composition, plating time, annealing temperature, and time were considered in order to prepare coatings with optimal mechanical properties.
39 citations
TL;DR: In this article, the phase structure characterization of Ni-B-Sn nano-coating was investigated using X-ray diffraction (XRD) and the crystal size was calculated using Scherrer's equation, which revealed that the addition of tin particle and heat treatment provides satisfactory enhancement in hardness and wear resistance of the coatings.
37 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