scholarly journals Synergetic Effects of Temperature and Perpendicular Magnetic Field on Zn-Ni Alloy Electrodepositing Process

2021 ◽  
Vol 33 (11) ◽  
pp. 2839-2844
Author(s):  
N. Benachour ◽  
S. Chouchane ◽  
J.P. Chopart

The zinc-nickel alloys were electrodeposited on stainless steel substrates during a chloride acid bath. The electroplating processes were investigated under a moderate perpendicular magnetic flux at uncommon temperatures. The coatings obtained were characterized by scanning microscopy (SEM) including EDX and X-ray diffraction (XRD). Chronopotentiometric curves were additionally implemented for electrochemical analysis. Structural analysis revealed that the obtained alloys consisted of a mix of the homogeneous phase γ-Ni3Zn22 and α-Zn-Ni at 70 ºC. The alloys variations observed within the chemical composition, crystallographic phases and morphology of the alloys. It is often explained particularly, by the progressive hydrogen reaction and therefore the evolution of the adsorbed intermediate species. The synergetic effect was significant at 70 ºC within the 1T field, including the appearance of normal co-deposition.

2008 ◽  
Vol 59 (9) ◽  
Author(s):  
Violeta Vasilache ◽  
Gheorghe Gutt ◽  
Traian Vasilache

The electrochemical deposition of zinc and combinations with elements of the 8th group of the Periodic System (nickel, cobalt, iron) have good properties for anticorrosive protection, compared with pure zinc. For steel pieces, these films delay apparition and formation of white and red iron oxide. We used solutions with different concentrations of zinc chloride, nickel chloride and potassium chloride. To analyze the results we used the optic microscope and the X-ray diffraction.


2005 ◽  
Vol 3 (3) ◽  
pp. 358-360 ◽  
Author(s):  
Jia Rong-Li ◽  
Wang Cheng-Yang ◽  
Zhu Bin

Superfine mesocarbon microbead powders (SFMCMBs) as the new supports for platinum electrocatalysts were first investigated. The Pt∕SFMCMB electrocatalysts were prepared by an impregnation-reduction method, with hexachloroplatinic acid as the platinum precursor and formaldehyde as the reducing agent. The catalysts were characterized with x-ray diffraction (XRD), field emission gun transmission electron microscope (TEM), and electrochemical analysis. TEM photos showed the platinum particles were dispersed uniformly on the surface of SFMCMBs and there existed a little aggregation of platinum particles in the Pt∕SFMCMB catalysts. The TEM photos showed the existence of the platinum on the supports where the average platinum particle size were 4-6nm. The electrochemical analysis proved that SFMCMBs are excellent candidates to be used as the support of platinum electrocatalyst for methanol electrochemical oxidation as the potential catalyst candidate for direct methanol fuel cells (DMFCs).


2012 ◽  
Vol 2012 ◽  
pp. 1-12 ◽  
Author(s):  
Jiang Zhang ◽  
Zheng-Hong Huang ◽  
Yong Xu ◽  
Feiyu Kang

The iodine-doped Bi2WO6(I-BWO) photocatalyst was prepared via a hydrothermal method using potassium iodide as the source of iodine. The samples were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscopy (TEM) and selected area electron diffraction (SAED), X-ray photoelectron spectroscopy (XPS), UV-vis diffuse reflectance spectroscopy (DRS), and photoluminescence (PL) spectroscopy. The photocatalytic activity of I-BWO for the degradation of rhodamine B (RhB) was higher than that of pure BWO and I2-BWO regardless of visible light (>420 nm) or ultraviolet light (<400 nm) irradiation. The results of DRS analysis showed that the I-BWO and I2-BWO catalysts had narrower band gaps. XPS analysis proved that the multivalent iodine species including I0and were coadsorbed on the defect surface of Bi2WO6in I-BWO. The enhanced PL intensity revealed that a large number of defects of oxygen vacancies were formed by the doping of iodine. The enhanced photocatalytic activity of I-BWO for degradation of RhB was caused by the synergetic effect of a small crystalline size, a narrow band gap, and plenty of oxygen vacancies.


2011 ◽  
Vol 399-401 ◽  
pp. 1447-1450
Author(s):  
Zhi Yong Yu ◽  
Han Xing Liu

The layered LiNi1/2Mn1/2O2 cathode materials were synthesized by a sol gel method. The effects of calcination temperature and time on the structural and electrochemical properties of the LiNi1/2Mn1/2O2 were investigated. The prepared samples were characterized by X-ray diffraction (XRD) and electrochemical analysis. The results revealed that the layered LiNi1/2Mn1/2O2 material could be optimal synthesized at temperature of 900°C for 10h. The sample prepared under the above conditions has the highest initial discharge capacity of 151 mAh/g and showed no dramatic capacity fading during 20 cycles between 2.5-4.5V at a current rate of 20mA/g.


Materials ◽  
2019 ◽  
Vol 12 (13) ◽  
pp. 2131 ◽  
Author(s):  
G.U. Ryu ◽  
G.M. Kim ◽  
Hammad R. Khalid ◽  
H.K. Lee

Blast furnace slag, an industrial by-product, is emerging as a potential raw material to synthesize hydroxyapatite and zeolite. In this study, the effects of temperature on the hydrothermal synthesis of hydroxyapatite-zeolite from blast furnace slag were investigated. Specimens were synthesized at different temperatures (room temperature, 50, 90, 120, or 150 °C). The synthesized specimens were analyzed qualitatively and quantitatively via X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), BET/BJH, and scanning electron microscopy/energy dispersive using X-ray analysis (SEM/EDX). It was found that the hydroxyapatite phase was synthesized at all the reaction temperatures, while faujasite type zeolite appeared in the specimens synthesized at 90 and 120 °C. Moreover, faujasite was replaced by hydroxysodalite in the specimens synthesized at 150 °C. Additionally, the crystals of the hydroxyapatite tended to become larger and total crystallinity increased as the reaction temperature increased.


2011 ◽  
Vol 399-401 ◽  
pp. 1487-1490
Author(s):  
Zhi Yong Yu ◽  
Han Xing Liu

The spinel-type Li4Ti5O12 cathode materials were synthesized by a self-combustion method. The effects of synthesis temperature on the structural and electrochemical properties of the Li4Ti5O12 were investigated. The prepared samples were characterized by X-ray diffraction (XRD), SEM, TEM and electrochemical analysis. The results revealed that pure phase and well-crystallized Li4Ti5O12 with nano-sized could be synthesized at a calcination temperature of 750°C. The sample prepared under the condition had the highest initial discharge capacity of 164 mAh/g and shown good capacity rentention during 50 cycles between 1.0-2.5V at 0.1C.


2010 ◽  
Vol 434-435 ◽  
pp. 743-746
Author(s):  
Shi Hai Zhao ◽  
Xiu Ming Jiang ◽  
Xu Guo Huai ◽  
Xiao Wei Fan

Laser cladding Fe-based alloy coatings with 0, 3, 6, 9, 12 and 15% Al2O3 xerogel on 45 steel substrates were prepared by 5kWCO2 continuous wave laser. The effect of the content of Al2O3 xerogel on the microstructure, microhardness and wear resistance of the coatings was investigated by scan electron microscope, X-ray diffraction. The results show that the microstructure and properties were different when the content of Al2O3 xerogel changed. The addition of Al2O3 xerogel can enhance the fluidity of molten liquid and refine the microstructure. Adding adequate amount of Al2O3 xerogel to Fe-based alloy can improve the hardness and the wear resistance due to the nano-Al2O3 particles on surfaces and the dispersion strengthening and hardening of nano- Al2O3 particles.


2003 ◽  
Vol 764 ◽  
Author(s):  
R. Nagarajan ◽  
J.H. Edgar ◽  
J. Pomeroy ◽  
M. Kuball ◽  
T. Aselage

AbstractThe chemical vapor deposition of icosahedral boron arsenide, B12As2, on 6H-SiC (0001) (on and off-axis) substrates was studied using hydrides as the reactants. The effects of temperature and reactant flow rates on the phases deposited and the crystal quality were determined. The growth rate increased with temperature from 1.5μm/h at 1100°C to 5 μm/h at 1400°C and decreased thereafter. X-ray diffraction revealed that the deposits were amorphous when the deposition temperature is below 1150° C. Above 1150°C, smooth B12As2 films were formed on 6H-SiC substrates with an orientation of (0001) B12As2 parallel to 6H-SiC (0001). Raman spectroscopy confirmed the strongly c-axis oriented nature of B12As2 film on 6H-SiC.


Materials ◽  
2020 ◽  
Vol 13 (14) ◽  
pp. 3082 ◽  
Author(s):  
Bogdan Istrate ◽  
Corneliu Munteanu ◽  
Stefan Lupescu ◽  
Romeu Chelariu ◽  
Maria Daniela Vlad ◽  
...  

In recent years, biodegradable Mg-based materials have been increasingly studied to be used in the medical industry and beyond. A way to improve biodegradability rate in sync with the healing process of the natural human bone is to alloy Mg with other biocompatible elements. The aim of this research was to improve biodegradability rate and biocompatibility of Mg-0.5Ca alloy through addition of Y in 0.5/1.0/1.5/2.0/3.0wt.%. To characterize the chemical composition and microstructure of experimental Mg alloys, scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), light microscopy (LM), and X-ray diffraction (XRD) were used. The linear polarization resistance (LPR) method was used to calculate corrosion rate as a measure of biodegradability rate. The cytocompatibility was evaluated by MTT assay (3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyltetrazolium bromide) and fluorescence microscopy. Depending on chemical composition, the dendritic α-Mg solid solution, as well as lamellar Mg2Ca and Mg24Y5 intermetallic compounds were found. The lower biodegradability rates were found for Mg-0.5Ca-2.0Y and Mg-0.5Ca-3.0Y which have correlated with values of cell viability. The addition of 2–3 wt.%Y in the Mg-0.5Ca alloy improved both the biodegradability rate and cytocompatibility behavior.


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