Untitled

Ivanov, M. V.; Лубнин, Е. Н.; Дровосеков, А. Б.

doi:10.1023/a:1022990726620

Cited by 7 publications

(4 citation statements)

References 1 publication

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The appearance of a shoulder on the highenergy wing of the W4f 5/2 line at a bond energy of 35.3 eV indicates the existence of an additional line related to the presence of oxidized tungsten. Taking into account the spin-orbital splitting energy, the line in this energy range is typical of tungsten ions W 4+ and W 6+ contained in WO 2 and WO 3 oxides [9]. In the bulk layers, where the content of oxygen admixtures did not exceed 5 to 7 at.…”

Section: Resultsmentioning

confidence: 94%

See 1 more Smart Citation

Chemically deposited Ni-W-B coatings: Composition, structure, and properties

et al. 2005

Self Cite

View full text Add to dashboard Cite

The effect of temperature and solution components of the chemical catalytic reduction on the composition of Ni-W-B alloy coatings is studied. The x-ray photoelectron spectroscopy in combination with the layer-by-layer profile analysis is used to determine the chemical state of elements and the composition of surface and bulk layers of the coatings containing 28 and 1.8 wt % (10 and 12 at. %) tungsten and boron, respectively. The surface of such coatings is shown to contain up to 90 and 80 at. % reduced nickel and boron, respectively. The deposits have amorphous structure. The effect of thermal treatment conditions on the structure and microhardness of the coatings is investigated. The coatings with a tungsten content of 10 at. % are shown to be nonmagnetic.

show abstract

Section: Resultsmentioning

confidence: 94%

“…One of the possible causes of this effect may be the diffusion of boron toward the surface during the thermal treatment of the coatings in air [9]. X-ray structure investigations of the coatings before and after their thermal treatment indicate that the coatings obtained from solution no.…”

Section: Resultsmentioning

confidence: 99%

Chemically deposited Ni-W-B coatings: Composition, structure, and properties

et al. 2005

Self Cite

View full text Add to dashboard Cite

show abstract

“…They are crystalline and more susceptible to oxidation than high B-alloyed amorphous Ni-B coatings. 30,31 Oxidation process of bulk crystalline Ni-W alloys ͑5.86 wt % W͒ prepared by arc melting of pure Ni and W, and consisting of a single fcc phase was studied after passivation. It was established that tungsten was preferentially oxidized, even though it was in a nickel-based solid solution.…”

Section: Resultsmentioning

confidence: 99%

Comparison of the Structure and Chemical Composition of Crystalline and Amorphous Electroless Ni-W-P Coatings

Valova

Armyanov

Franquet

et al. 2004

J. Electrochem. Soc.

View full text Add to dashboard Cite

Electroless deposition was applied to prepare Ni-W-P coatings of two types: crystalline, with low P and W, and amorphous with high W content. Their morphology was studied by atomic force microscopy. Polycrystalline Ni-W-P alloys consist of grains of stacked plates ͑lamellas͒, as it was revealed by transmission electron microscopy. The coatings exhibit a ͗100͘ texture. X-ray diffraction and electron diffraction analysis demonstrated the unit cell parameter of the crystalline phase in Ni-W-P is practically equal to that of pure Ni. This implies W and P are localized along the grain boundaries. The Warren/Averbach method was applied to determine microstrain and size of coherent scattering domains. The crystalline structure promotes the surface oxidation of Ni-W-P to higher extent in comparison with the amorphous structure. X-ray photoelectron spectroscopy analysis demonstrated the presence of oxygen and carbon in the bulk of the crystalline Ni-W-P coatings in larger quantities than in the amorphous. In the crystalline coatings in addition to oxygen and carbon, scanning Auger electron spectroscopy showed the presence of nitrogen. It is supposed that all these elements come from ligand residues adsorbed at the grain boundaries during coating growth. Nanoindentation tests indicated that amorphous Ni-W-P samples display more uniform surface mechanical properties at the nanometer scale than the crystalline ones.

show abstract

“…The observed trend can be explained based on the chemical nature of the EL Ni-B coating on the surface as well as the layers underneath it. Based on the layer-by-layer composition analysis performed using XPS after etching of the EL Ni-B coating, Ivanov et al 28 Fig. 1), which indicates the ability of the EL Ni-B coating to provide a good electrical contact.…”

Section: Contact Resistance Of the El Ni-b Coatingsmentioning

confidence: 99%

EVALUATION OF THE PERFORMANCE OF ELECTROLESS Ni–B COATED BRASS CONTACTS UNDER FRETTING CONDITIONS

2008

View full text Add to dashboard Cite

The performance of electroless (EL) Ni – B coated brass contacts under fretting conditions was evaluated. The contact resistance of EL Ni – B coated brass contact was measured as a function of fretting cycles. The surface profile and wear depth of the fretted zone were measured using laser scanning microscope. The study reveals that EL Ni – B coated contacts exhibit better performance under fretting conditions. However, at conditions which are prone for severe oxidation such as, low frequency (3 Hz) or high temperature (155°C), EL Ni – B coated contacts fail to exhibit a better stability. The quick removal of the oxide film by fretting motion, rapid oxidation of the fresh metallic particles and trapping of the oxidation products in the remaining coating, cause the contact resistance to increase to unacceptable levels at such conditions. The study concludes that EL Ni – B coating is not a suitable choice for connector contacts that could experience fretting under highly oxidizing conditions.

show abstract

Untitled

Cited by 7 publications

References 1 publication

Chemically deposited Ni-W-B coatings: Composition, structure, and properties

Chemically deposited Ni-W-B coatings: Composition, structure, and properties

Comparison of the Structure and Chemical Composition of Crystalline and Amorphous Electroless Ni-W-P Coatings

EVALUATION OF THE PERFORMANCE OF ELECTROLESS Ni–B COATED BRASS CONTACTS UNDER FRETTING CONDITIONS

Contact Info

Product

Resources

About