scholarly journals The Electrodeposition of Nickel Coatings, Modified Ultrafine Diamonds

2016 ◽  
Vol 17 (3) ◽  
pp. 435-439 ◽  
Author(s):  
V.A. Zabludovsky ◽  
V.V. Tytarenko

The polarization analysis of nickelwhen the concentration of ultrafine particles of diamond (UFD) in the electrolyte solution and its frequency mixing. It was found that the addition of nanodiamond particles in an aqueous electrolyte solution causes a shift reduction potential nickel electronegative region, increase resistance to charge transfer and the formation of a fine-grained, close-packed surfaces that determined the increase of microhardness and wear resistance of the metal coating.

2021 ◽  
Vol 21 (1) ◽  
pp. 32-48
Author(s):  
Svetlana S. Popova ◽  
◽  
Hussein Ali Hussein ◽  
Lyubov’ N. Olshanskaya ◽  
Sergei V. Arzamastsev ◽  
...  

It was established that at the cathodic treatment of titanium in aqueous dimethyl sulfoxide solutions of sodium molybdate, containing phosphoric acid, at the potential of the cathodic incorporation of sodium (Ec = −2.6 V) in the potentiostatic mode, the composition formed on the electrode surface layer depended not only on the composition of the solution, but also on the volume ratio of the aqueous electrolyte solution and the organic solvent (dimethyl sulfoxide).


2021 ◽  
Author(s):  
Linlin ZHANG ◽  
Dawei ZHANG

Ni-Co-W composite coatings modified by different contents of Co-based alloy powder in the Ni-based alloy with 35 wt.% WC (Ni35WC) were deposited on stainless steel by laser cladding. The influence of compositional and microstructural modification on the wear properties has been comparatively investigated by XRD, SEM, and EDS techniques. It was found that the austenite dendrites in the modified coating adding 50 wt.% Co-based alloy were refined and a lot of Cr23C6 or M23(C, B)6 compounds with fine lamellar feature were formed around austenitic grain boundaries or in the intergranular regions. The contribution of element Co to the modification of Ni35WC coating is that it cannot only promote the formation of more hard compounds to refine austenite grains, but also refine the size of precipitates, and change the phase type of eutectic structure as a result of disappeared Cr boride brittle phases. A noticeable improvement in wear resistance is obtained in the Ni35WC coating with 50 wt.% Co-based alloy, which makes the wear rate decreased by about 53 % and 30% by comparison to that of the substrate and the Ni35WC coating, respectively. It is suggested that the improvement is closely related to the composite coating being strengthened owing to the increase of coating hardness, formation of a fine-grained microstructure caused by Co, and fine hard precipitate phases in the eutectic structure.


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