Formation and Structural Characterization of Electroless Ni-B-P Ternary Alloy Coatings

2014 ◽  
Vol 592-594 ◽  
pp. 385-390 ◽  
Author(s):  
P.G. Venkatakrishnan ◽  
S.S. Mohamed Nazirudeen ◽  
T.S.N. Sankara Narayanan
Keyword(s):  
Electroless Plating ◽  
Morphological Characteristics ◽  
Reducing Agents ◽  
Sodium Hypophosphite ◽  
Electron Microscopic ◽  
Plating Bath ◽  
Peak Broadening ◽  
Chloride Hexahydrate ◽  
Electroless Ni

The aim of the present investigation is to study the formation of electroless Ni-B-P alloy coatings and structural and morphological characterization of various coatings with different boron and phosphorous content. An alkaline plating bath with nickel chloride hexahydrate as the source of nickel ions and sodium borohydride and sodium hypophosphite as reducing agents were used for the formation of electroless Ni-B-P alloy coatings. The influence of changes in the concentrations of the reducing agents in the electroless plating bath on the chemical composition, structural and morphological characteristics of the coatings were studied. Scanning electron microscopic studies revealed that the surface morphology of Ni-B-P alloy coatings changed from corn cob-like structure to cauliflower-like structure with increasing borohydride concentration in electroless plating bath, whereas increase in hypophosphite concentration favoured sideway growth, thereby decreased the surface roughness of the Ni-B-P alloy coatings. The peak broadening in the X-Ray Diffraction profiles indicates the large reduction in the crystallite size of the electroless Ni-B-P alloy coatings with increasing boron content in the coating (i.e. for higher borohydride concentration in the plating bath).

Tribocorrosion behavior of electroless Ni-P/Ni-B duplex coating on AA7075 aluminum alloy

2019 ◽  
Vol 71 (5) ◽  
pp. 630-635 ◽  
Author(s):  
Harun Mindivan
Keyword(s):  
Aluminum Alloy ◽  
Surface Characterization ◽  
X Ray Diffraction ◽  
Electron Microscopic ◽  
Content Type ◽  
Duplex Coating ◽  
Scanning Electron Microscopic ◽  
Electroless Ni ◽  
Insight Into

Purpose 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. Design/methodology/approach 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. Findings 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. Originality/value 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.

Improvement on Hardness of 6061 Al Alloy Using an Electroless Ni-P Coating

2010 ◽  
Vol 26-28 ◽  
pp. 293-296 ◽  
Author(s):  
Wen Feng Qin ◽  
Jiang Long ◽  
Feng Liu
Keyword(s):  
Surface Morphology ◽  
Sodium Hypophosphite ◽  
Al Alloy ◽  
Plating Bath ◽  
Nodular Structure ◽  
P Content ◽  
Scanning Electron Microcopy ◽  
Alloy Plating ◽  
6061 Al Alloy ◽  
Electroless Ni

The surface morphology and hardness of electroless Ni–P alloy plating on 6061 aluminum alloys substrate in an alkaline plating bath with sodium hypophosphite as reducing agent were investigated. The effects of bath pH on the plating rate, compositions and surface morphology of theelectroless Ni-P deposits were studied. The results showed the deposition rate of the electroless Ni–P deposits increased with the rise of the bath pH, while the P content decreased. Scanning electron microcopy (SEM) of the deposits showed nodular structure for the deposits. Hardness data of the Ni-P coatings indicated that electroless Ni–P plating could obviously improve the hardness of 6061aluminum alloy.

Effect of Bath Compositions on the Properties of Electroless Ni-Cu-P Alloys on Aluminum

2011 ◽  
Vol 117-119 ◽  
pp. 1276-1279 ◽  
Author(s):  
Xi Ran Wang ◽  
Xin Gang Hu ◽  
Wei Yuan Li
Keyword(s):  
Corrosion Resistance ◽  
Electroless Plating ◽  
Sodium Citrate ◽  
Nickel Sulfate ◽  
Sodium Hypophosphite ◽  
Micro Hardness ◽  
X Ray ◽  
Plating Method ◽  
The Matrix ◽  
Electroless Ni

In this work, the electroless plating Ni-Cu-P on aluminium is obtained successfully by direct Ni-Cu-P plating method. The effect of bath compositions on the electroless plating rate and the properties of the electroless Ni-Cu-P deposits was studied by orthogonal test. The corrosion resistance, hardness, surface morphology and components of the coating were studied by using electrochemical workstation, digital micro-hardness SEM and EDS. The optimum bath formula obtained is 0.6g/L copper sulfate, 30g/L nickel sulfate, 35g/L sodium citrate, 25 g/L sodium hypophosphite, 20g/L acetic anhydride and right amount of self-made additive. The deposition rate, hardness and corrosion resistance are all good. The adhesion between the deposits and the matrix is better. The deposits is smooth and uniformity, smooth by SEM. The deposit contains Ni 78.90%, Cu 8.65%, P 12.46% by the analyses of energy disperse X-ray.

Preparation and Characterization of Cr-Co-P Alloy Coating Electrodeposited from Trivalent Chromium Solution

2008 ◽  
Vol 373-374 ◽  
pp. 277-280
Author(s):  
Ye Ming Zhang ◽  
Da Jing Fang ◽  
Long Hao ◽  
An Lin ◽  
Fu Xing Gan
Keyword(s):  
Ph Value ◽  
Alloy Coating ◽  
Trivalent Chromium ◽  
Ammonium Citrate ◽  
Sodium Hypophosphite ◽  
Plating Bath ◽  
Electro Deposition ◽  
Iridium Dioxide ◽  
Pure Graphite

Cr-Co-P alloy coating was prepared from trivalent chromium bath and the appearance and performances of the coating were characterized. The Cr-Co-P alloy electroplating bath was prepared through orderly adding cobalt chloride, sodium hypophosphite monohydrate, urea, sodium format, ammonium citrate tribasic, boric acid, and ammonium brome into distilled water. Optimum plating crafts were determined as follows: pH value 1.5~3.0, temperature 25~45°C, plating time 1~15 minutes, and current density 5~25A·cm-2. Reticulate iridium dioxide coating electrode or highly pure graphite electrode were adopted as anode. And electro deposition experiments were carried out with air disturbance. The surfaces of deposited coatings are silvery white, bright and smooth. The Cr-Co-P alloy coatings were characterized by scanning electronic microscope (SEM). The results proved that P is favour to the improvement of deposit corrosion resistance. In addition, Cobalt atoms are in favor of enhancing throwing power and cover power of plating baths. Via adjusting plating bath, the electro-deposition rate could reach at 1.0~1.3μm·min-1, and the contents of P and Co could be controlled in 15~25% and 10~65%.

Study on Ni-P-Nanometer Diamond Composite Electroless Plating for 2A12 Aluminum Alloy

2012 ◽  
Vol 472-475 ◽  
pp. 2926-2929 ◽  
Author(s):  
Gang Yi Cai ◽  
Bing Yi Yan ◽  
Xue Feng Shi
Keyword(s):  
Aluminum Alloy ◽  
Adhesion Strength ◽  
Deposition Rate ◽  
Sodium Acetate ◽  
Orthogonal Design ◽  
Nickel Sulfate ◽  
Sodium Hypophosphite ◽  
Plating Bath ◽  
Diamond Composite ◽  
Electroless Ni

On the basis of electroless Ni-P plating, the technique of electroless Ni-P-nanometer diamond composite plating for 2A12 aluminum alloy was studied. The table of L9 (34) of orthogonal design was adopted in the experiment. The optimal formulation of plating bath for 2A12 aluminum alloy was determined. The effect of bath composition on deposition rate and adhesion strength was studied. The results show that the order of marked factors on deposition rate from large to small is nanometer diamond, sodium acetate, nickel sulfate hexahydrate and sodium hypophosphite in turn, while for adhesion strength is nanometer diamond, sodium acetate, sodium hypophosphite and nickel sulfate hexahydrate. The optimal plating formulation are consisted of nanometer diamond (2g/L), NiSO4•6H2O (30g/L), NaH2PO2•H2O (30g/L) and CH3COONa (15g/L), which is operated at 80~85°C, pH (4.5). The microstructure of coating plated with optimal process is cellular structure, which is homogeneous, compact and good brightness, and its deposition rate is 17.0μm/h.

Effect of Stabilizers on Electromagnetic Property of Electroless Ni Coating on Aluminum Powder

2013 ◽  
Vol 750-752 ◽  
pp. 2070-2073 ◽  
Author(s):  
Zhe Li ◽  
Zhi Dong Xia ◽  
Xiao Ya Wang
Keyword(s):  
Electrical Conductivity ◽  
Aluminum Powder ◽  
Electroless Plating ◽  
Electromagnetic Property ◽  
Plating Bath ◽  
Aluminum Powders ◽  
Conductive Fillers ◽  
Electroless Ni

Nickel-coated aluminum powders used as conductive fillers were prepared with different stabilizers added in electroless plating bath. Their Electrical conductivity and magnetoconductivity were measured to evaluate the effect of stabilizers on Nickel-coated aluminum powders. The results suggested that the electrical conductivity of Ni-coated aluminum powder was dependent on the variety and content of stabilizers while the magnetoconductivity was irrelevant to the stabilizers. It was proved that the concentration and variety of stabilizer had different influence on the microstructure of coating and changed the electrical conductivity of Ni-coated aluminum powder thereby.

Electron Microscopic Detection and Characterization of Nonhuman Primate Enteric Viruses

1982 ◽  
Vol 40 ◽  
pp. 306-307
Author(s):  
G. C. Smith ◽  
R. L. Heberling ◽  
S. S. Kalter
Keyword(s):  
Electron Microscopy ◽  
Animal Model ◽  
Nonhuman Primate ◽  
Clinical Condition ◽  
Intestinal Tract ◽  
Enteric Viruses ◽  
Electron Microscopic ◽  
Microscopic Detection

A number of viral agents are recognized as and suspected of causing the clinical condition “gastroenteritis.” In our attempts to establish an animal model for studies of this entity, we have been examining the nonhuman primate to ascertain what viruses may be found in the intestinal tract of “normal” animals as well as animals with diarrhea. Several virus types including coronavirus, adenovirus, herpesvirus, and picornavirus (Table I) were detected in our colony; however, rotavirus, astrovirus, and calicivirus have not yet been observed. Fecal specimens were prepared for electron microscopy by procedures reported previously.

Cell Wall Ultrastructure in Three Strains of a Cariogenic Streptococcus

1971 ◽  
Vol 29 ◽  
pp. 338-339
Author(s):  
M. J. Kramer ◽  
Alan L. Coykendall
Keyword(s):  
Cell Wall ◽  
Dental Caries ◽  
Streptococcus Mutans ◽  
Microscopic Study ◽  
Electron Microscopic Study ◽  
Genetic Heterogeneity ◽  
Morphological Characteristics ◽  
Electron Microscopic ◽  
Dna Reassociation ◽  
Wall Ultrastructure

During the almost 50 years since Streptococcus mutans was first suggested as a factor in the etiology of dental caries, a multitude of studies have confirmed the cariogenic potential of this organism. Streptococci have been isolated from human and animal caries on numerous occasions and, with few exceptions, they are not typable by the Lancefield technique but are relatively homogeneous in their biochemical reactions. An analysis of the guanine-cytosine (G-C) composition of the DNA from strains K-1-R, NCTC 10449, and FA-1 by one of us (ALC) revealed significant differences and DNA-DNA reassociation experiments indicated that genetic heterogeneity existed among the three strains. The present electron microscopic study had as its objective the elucidation of any distinguishing morphological characteristics which might further characterize the respective strains.

The Immuno-Electron Microscopic Localization of the Mo-Fe Protein Component of Nitrogenase in Cells of Azotobacter Vinelandii

1973 ◽  
Vol 31 ◽  
pp. 574-575
Author(s):  
J. T. Stasny ◽  
R. C. Burns ◽  
R. W. F. Hardy
Keyword(s):  
Cellular Localization ◽  
Direct Evidence ◽  
Azotobacter Vinelandii ◽  
Intracellular Localization ◽  
Protein Component ◽  
Electron Microscopic ◽  
Thin Sections ◽  
Fe Protein ◽  
Intracytoplasmic Membranes

Structure-functlon studies of biological N2-fixation have correlated the presence of the enzyme nitrogenase with increased numbers of intracytoplasmic membranes in Azotobacter. However no direct evidence has been provided for the internal cellular localization of any nitrogenase. Recent advances concerned with the crystallizatiorTand the electron microscopic characterization of the Mo-Fe protein component of Azotobacter nitrogenase, prompted the use of this purified protein to obtain antibodies (Ab) to be conjugated to electron dense markers for the intracellular localization of the protein by electron microscopy. The present study describes the use of ferritin conjugated to goat antitMo-Fe protein immunoglobulin (IgG) and the observations following its topical application to thin sections of N2-grown Azotobacter.

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