Structure and Electrochemical Characterization of Electrolytic Ni-Co-P and Ni-W-P Layers

2006 ◽  
Vol 514-516 ◽  
pp. 460-464 ◽  
Author(s):  
Magdalena Popczyk ◽  
Antoni Budniok ◽  
Henryk Scholl ◽  
Tadeusz Blaszczyk

Ni-P, Ni-Co-P and Ni-W-P layers were obtained in galvanostatic conditions, at the current density jdep= 0.200 A cm-2. The X-ray diffraction method was used to determine phase composition of the layers and the atomic absorption spectrometry was applied to specify their chemical composition. A metallographic, stereoscopic and tunneling microscope and also Form Talysurf-type profilograph were used for cross-section and surface morphology characterization of the layers. The behaviour of obtained layers was investigated in the processes of hydrogen and oxygen evolution from 5 M KOH using voltammetry method. It was ascertained that, introduction of cobalt or tungsten into Ni-P matrix, lead to obtain the layers about very developed surface. Thus obtained layers may be useful in application as electrode materials in electrochemistry.

2015 ◽  
Vol 228 ◽  
pp. 299-304
Author(s):  
Magdalena Popczyk ◽  
B. Łosiewicz ◽  
Eugeniusz Łągiewka ◽  
A. Budniok

The Ni-P, Ni-Co-P and Ni-P+Co coatings were obtained in galvanostatic conditions at the current density ofjdep= -200 mA cm-2. A stereoscopic microscope was used for surface morphology characterization of the coatings. The X-ray diffraction (XRD) method was used to determine phase composition of the coatings and the atomic absorption spectrometry (AAS) was applied to specify their chemical composition. The behavior of the obtained coatings was investigated in the process of hydrogen evolution reaction (HER) from 5 M KOH using steady-state polarization and electrochemical impedance spectroscopy (EIS) methods. It was found that introduction into Ni-P amorphous matrix powder of cobalt produced porous electrode materials which could be used for the HER.


2015 ◽  
Vol 228 ◽  
pp. 163-167
Author(s):  
Magdalena Popczyk ◽  
B. Łosiewicz ◽  
Eugeniusz Łągiewka ◽  
A. Budniok

Electrodeposited Ni-P, Ni-W-P, Ni-P+W and Ni-P+NiO+W coatings were obtained in the galvanostatic conditions at the current density jdep = -200 mA cm-2. A stereoscopic microscope was used for surface characterization of the coatings. The phase composition of the coatings was determined using X-ray diffraction (XRD) method. The chemical composition of the deposits was determined using atomic absorption spectroscopy (AAS). It was found out that the introduction of the tungsten powder in one case, and the nickel oxide and tungsten powder in the other into the electrolytic Ni-P matrix results in obtaining the coatings with a very rough surface. The coatings obtained in this way may be useful while applying them as electrode materials in electrochemistry.


2015 ◽  
Vol 228 ◽  
pp. 158-162
Author(s):  
Magdalena Popczyk ◽  
B. Łosiewicz ◽  
Eugeniusz Łągiewka ◽  
A. Budniok

The Ni-P and Ni-Co-P coatings were electrodeposited at the deposition current density ofjdep= -20 mA cm-2. Thermal treatment of these coatings was conducted in air at 400oC for 1 h. Scanning electron microscopy (SEM) was used for surface morphology characterization of the coatings. Phase composition was investigated by X-ray diffraction (XRD) method. Atomic absorption spectrometry (AAS) was applied to specify chemical composition of obtained coatings. It was found that introduction of Co into amorphous Ni matrix caused the surface development of the obtained deposit. The Ni-P coating revealed an amorphous structure. The Ni-Co-P coating was formed of the amorphous matrix and the amorphous alloy ingredient. Thermal treatment of the coatings allowed to obtain new multi-phase materials with slightly developed surface.


2006 ◽  
Vol 514-516 ◽  
pp. 465-469 ◽  
Author(s):  
Jolanta Niedbała

The electrochemical layers with molybdenum were obtained by electrodeposition from citrate bath. The process was carried out under galvanostatic conditions. Structural investigations were conducted by X-ray diffraction method. It was ascertained that electrodeposited Ni-Mo-P alloys are characterized by amorphous structure, Ni-Mo alloys are characterized by nanocrystalline structure whereas Ni+Mo composite layers have a crystalline structure. The chemical composition was determined using X-ray fluorescence spectroscopy method. It was stated that Ni-Mo-P alloys contain 75%Ni, 10%Mo and 15%P, the Ni-Mo alloys contain 90%Ni and 10%Mo, Ni+Mo composite layers contain 90%Ni and 10%Mo. These layers were characterized by electrochemical methods (j=f(E) voltammetry and corrosion resistance by Stern method). The results of corrosion tests show that from among obtained layers the highest corrosion resistances exhibit nanocrystalline Ni-10%Mo alloys.


2014 ◽  
Vol 660 ◽  
pp. 942-946
Author(s):  
Mohamad Firdaus Abdul Wahid ◽  
C.M. Mardziah ◽  
Koay Mei Hyie ◽  
N.R. Nik Roselina

Hydroxyapatite was prepared by using precipitation method. The substitution of zinc ions in hydroxyapatite structure was studied by several characterization techniques. Several concentration of zinc ions were substituted into hydroxyapatite. Characterization technique such as X-ray diffraction method was used to study the phase changes and the lattice parameters with the addition of zinc. Field emission scanning electron microscopy was used to examine the influence of zinc on the crystal size and the morphology of the as-synthesized powders. Based on X-ray diffraction result, the addition of zinc affects the lattice parameters and phase. The result showed that zinc ions were substituted in the structure. As zinc substitution increased, the lattice parameters a and c decreased. The crystal shape of hydroxyapatite without zinc ions was regular shapes while hydroxyapatite with zinc ions was irregular and also tends to agglomerates with single particle was calculated about 28 - 34 nm .


2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
K. Rajesh ◽  
B. Milton Boaz ◽  
P. Praveen Kumar

Single crystals of pure and Lanthanum doped L-Alanine Tartrate were grown by slow evaporation method. The cell parameters were determined using single crystal X-ray diffraction method. To improve the physical properties of the LAT crystal, Lanthanum dopant was added by 2 mol%. ICP studies confirm the presence of Lanthanum in the grown LAT crystal. Transparency range of the crystal was determined using UV-VIS-NIR spectrophotometer. The functional groups of pure and doped LAT crystals were analyzed by FT-IR spectroscopy. Using Vickers microhardness tester, mechanical strength of the material was found. Dielectric studies of pure and doped LAT single crystals were carried out. The doped LAT crystal is found to have efficiency higher than that of pure LAT crystal.


2021 ◽  
Author(s):  
Joanna Hrabia-Wiśnios ◽  
Beata Leszczyńska-Madej ◽  
Marcin Madej ◽  
Aleksandra Węglowska

Abstract The paper presents the results of research on the microstructure and selected mechanical properties of the SnSbCu bearing alloy after friction stir processing (FSP). The Whorl tool was used for modification; the process was carried out using two rotational speeds of the tool: 280 and 450 RPM and a constant linear speed of 355 mm/min. Microstructure studies were performed employing the techniques of light microscopy and scanning electron microscopy along with analysis of the chemical composition of micro-areas. Additionally, the phase composition was investigated by means of the X-ray diffraction method and statistical analysis of the precipitates present in the investigated alloy. In addition, hardness, flexural strength and uniaxial compression tests were performed before and after FSP modification. It was proved that using FSP to modify the SnSbCu alloy promotes refinement and homogenization of the microstructure, as well as improvement of the flexural strength, whereas no changes in the hardness level were found.


Open Physics ◽  
2013 ◽  
Vol 11 (2) ◽  
Author(s):  
Aleksandra Mielewczyk-Gryn ◽  
Tomasz Lendze ◽  
Katarzyna Gdula-Kasica ◽  
Piotr Jasinski ◽  
Andrzej Krupa ◽  
...  

AbstractA composite of CaTi0.9Fe0.1O3 and electrolyte material, i.e. magnesium doped La0.98Mg0.02NbO4 was prepared and studied. The phase content and the sample microstructure was examined by an X-ray diffraction method and scanning electron microscopy. EDS measurements were done both for composite samples and the diffusion couple. The electrical properties were studied by four terminal DC method. The high-temperature interaction between the two components of the composite has been observed. It has been suggested that lanthanum diffused into the perovskite phase and substituted for calcium whereas calcium and niobium formed the Ca2Nb2O7 pyrochlore phase. At 1500°C very large crystallites of the pyrochlore were observed. Regardless of strong interaction between the composite components, its total conductivity was weakly dependent on the sintering temperature.


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