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Features of Structure of Electrodeposited Metals Resulting from Exposure to External Force Parallel, Normal or Inclined to the Crystallization Front
Issue:
Volume 4, Issue 3-1, June 2015
Pages:
1-14
Received:
23 May 2015
Accepted:
25 May 2015
Published:
18 June 2015
Abstract: To prove whether phase formation in an electrochemically deposited metal indeed passes a liquid state stage, experiments involving application of an external force during electrodeposition were carried out and structural features of deposit were subsequently determined. Following experimental facts in support of the phenomenon in point were observed: (1) occurrence of anisotropic pattern of electrodeposits of metals being electrodeposited, smoothing out of deposits surface morphology and reduction in their surface roughness arising from exposure to a minor external force parallel to the crystallization front; (2) refinement of intracrystalline structure and of surface morphology of metals being electrodeposited under exposure to a minor external force normal to the crystallization front; (3) dislocation density rise in metals being electrodeposited under exposure of a minor external force normal to the crystallization front; (4) surface layers plastic deformation in metals being electrodeposited by solid particles travelling due to action of minor external force inclined to the crystallization front; and (5) occurrence of indents from solid particles representing the particles' shape and morphology at sites of the particles' separation from deposit surface in metals being electrodeposited under exposure to minor external force inclined to the crystallization front.
Abstract: To prove whether phase formation in an electrochemically deposited metal indeed passes a liquid state stage, experiments involving application of an external force during electrodeposition were carried out and structural features of deposit were subsequently determined. Following experimental facts in support of the phenomenon in point were observe...
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Pulse Electrodeposition of Sn-Ni-Fe Alloys and Deposit Characterisation for Li-ion Battery Electrode Applications
G. B. Lak,
C. Chisholm,
M. El-Sharif
Issue:
Volume 4, Issue 3-1, June 2015
Pages:
15-20
Received:
28 April 2015
Accepted:
14 May 2015
Published:
18 June 2015
Abstract: Characterisation of Sn-Ni-Fe ternary alloy deposits obtained by pulse electrodeposition show that novel alloys of varying composition can be successfully deposited exhibiting amorphous structures using specific on/off pulse plating parameters for electrodeposition in combination with an electrolyte based on gluconate as a complexing agent. The deposits obtained exhibited high quality bright metallic surface morphologies combined with a distinct pronounced spherical/nodular grain structure across a range of average current densities. The influence of on/off period pulse current and the effect of the average current density on the surface morphology of the electrodeposited films were studied using Scanning Electron Microscopy (SEM). The cathode efficiency results obtained show that the pulse electrodeposition process chosen is significantly more efficient than the constant current electrodeposition. Results suggest that the substrate surface deformation condition and preparation are critically important in achieving a surface morphology suitable for an effective Sn-Ni-Fe alloy battery electrode. The alloy deposits with a morphology, which exhibits a high surface area per unit volume, are shown to be promising as an alternative anode material for lithium ion batteries.
Abstract: Characterisation of Sn-Ni-Fe ternary alloy deposits obtained by pulse electrodeposition show that novel alloys of varying composition can be successfully deposited exhibiting amorphous structures using specific on/off pulse plating parameters for electrodeposition in combination with an electrolyte based on gluconate as a complexing agent. The depo...
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Electrodeposition of Nickel-Zinc Alloy from a Sulfamate Bath
Issue:
Volume 4, Issue 3-1, June 2015
Pages:
21-26
Received:
13 May 2015
Accepted:
19 May 2015
Published:
18 June 2015
Abstract: The electrodeposition of Ni-Zn alloy coatings having high nickel content (74-97 wt%) from a sulfamate bath was studied. The investigation was performed by means of cyclic voltammetry, potentiostatic electrodeposition, X-ray diffraction, scanning electron microscopy and energy dispersive X-ray analysis. The effect of the experimental parameters (deposition potential, zinc concentration, addition of sodiumdodecylsulphate) on the coating composition, morphology and structure was studied. The obtained results show that the addition of Zn2+ to the deposition bath leads to a strong decrease in the cathodic current density, indicating a remarkable inhibition of Ni reduction. Even if anomalous codeposition was observed for all the studied experimental conditions, nickel rich alloys were obtained due to the mass transport control. A sudden decrease in the current efficiency, indicating a decrease in the hydrogen overvoltage, was found on increasing zinc percentage in the alloy over than about 15 wt%. The incorporation of Zn in the cfc Ni lattice up to about 20 wt% leads to a grain refinement and to an increase in hardness.
Abstract: The electrodeposition of Ni-Zn alloy coatings having high nickel content (74-97 wt%) from a sulfamate bath was studied. The investigation was performed by means of cyclic voltammetry, potentiostatic electrodeposition, X-ray diffraction, scanning electron microscopy and energy dispersive X-ray analysis. The effect of the experimental parameters (dep...
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Changes in the Structure and Properties of Electrodeposited Metal Coatings in the Process of Aging
Ilya Kovenskiy,
Anatoliy Venediktov
Issue:
Volume 4, Issue 3-1, June 2015
Pages:
27-32
Received:
10 April 2015
Accepted:
3 May 2015
Published:
18 June 2015
Abstract: The most commonly used in the industry metal coatings of Cr, Fe, Co, Ni, Cu, Sb, Bi, Pb, Sn were investigated. The influence of electrodeposition conditions on the formation of the structure and properties of coatings has been established, their changes during the aging process were studied and the conditions of heat treatment ensuring the in-service stability of the properties of the coatings have been determined.
Abstract: The most commonly used in the industry metal coatings of Cr, Fe, Co, Ni, Cu, Sb, Bi, Pb, Sn were investigated. The influence of electrodeposition conditions on the formation of the structure and properties of coatings has been established, their changes during the aging process were studied and the conditions of heat treatment ensuring the in-servi...
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Structural Features of Electrodeposited Metals as a Result of Ultra-Rapid Solidification of a Highly Supercooled Liquid Metal Phase
Issue:
Volume 4, Issue 3-1, June 2015
Pages:
33-40
Received:
27 May 2015
Accepted:
28 May 2015
Published:
18 June 2015
Abstract: With a view to validating the existence of the phenomenon of phase formation via a liquid state stage in metals being electrodeposited, experiments were carried out to reveal electrodeposited metal's structural features typical of metals produced by solidification at ultra-high rates under high supercooling, and to establish consistent changes in metal structural characteristics with increasing degree of supercooling in electrodeposition. Following experimental facts in favour of the existence of the phenomenon in point were found: (1) occurrence of spherulites and pentagonal quasicrystals in electrodeposit layers adjoining the cathode, the occurrence being typical of metals produced by ultra-rapid solidification of a highly supercooled liquid metal phase; (2) emergence of the electrodeposited metals solely in a spherulitic form when transition of spherulitic growth to drusy growth with increasing deposit thickness was prevented; and (3) regular change in characteristics of point, linear and planar defects in the crystalline lattice with increasing degree of supercooling in electrodeposition of metals.
Abstract: With a view to validating the existence of the phenomenon of phase formation via a liquid state stage in metals being electrodeposited, experiments were carried out to reveal electrodeposited metal's structural features typical of metals produced by solidification at ultra-high rates under high supercooling, and to establish consistent changes in m...
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