Preparation of Porous Metallic Nickel by Jet Electrodeposition

2011 ◽  
Author(s):  
Li-da Shen ◽  
Zong-jun Tian ◽  
Zhi-dong Liu ◽  
Yin-hui Huang
Keyword(s):  
Porous Structure ◽  
Energy Absorption ◽  
Current Density ◽  
Absorption Rate ◽  
Porous Metal ◽  
Metallic Nickel ◽  
Micro Hardness ◽  
Porous Nickel ◽  
Dendritic Crystal ◽  
Jet Electrodeposition

The theory and related technology of porous metallic nickel by using jet electrodeposition (JED) are reviewed, and preparation of different porosities of the porous metallic nickel samples was made by the self-developed device. The surface morphology, microstructure, grain size of the micro-cell structure of deposition were studied and analyzed by SEM, and the mechanical properties of the sample, such as surface micro hardness and compressive property were also studied. The results are as follows: the process of porous nickel preparation by jet electrodeposition mentioned in paper is capable of preparing porous metal with dendritic crystal structure as the subject porous structure. Ejection electrodeposition has great advantages in machining efficiency and cost compared with porous metal preparation process of traditional electrodeposition. The porous nickel metal sample prepared, in respects of pore distribution and porosity, are affected by electrodeposited porous dendritic crystal layers. The formula Bath A, which has a relatively low concentration of nickel ions, can make the preparation of porous dendrite structure more favorable in the way that it has more uniform compactness. Current density is the key indicator in forming ideal branched crystal; more than 60A/dm2 can make the process access to a good working state. With the increase in current density, the dendrite formation of porous structure becomes more compact. The porosity of the prepared sample is 48.7%, using jet scanning electrodeposition with the current density at 80A/dm2. The surface micro hardness of the sample reaches HV 315. The compressive yield stress of porous Nickel is 11.35 MPa, which has a large number of plastic deformations of the absorption capacity. From original data of sample energy absorption rate and fitting curve, it is known that there comes great plastic deformation, which gives the sample better absorption ability and relatively greater energy absorption rate at a relatively low flow stress.

Preparation and Characterization of Bulk Porous Nickel Fabricated by Novel Scanning Jet Electrodeposition

2014 ◽  
Vol 532 ◽  
pp. 562-567
Author(s):  
Kai Gong ◽  
Guo Qing Xu ◽  
Zong Jun Tian
Keyword(s):  
Electrolyte Solution ◽  
Current Density ◽  
Porous Metal ◽  
Growth Conditions ◽  
Preparation Technique ◽  
Porous Nickel ◽  
Scanning Rate ◽  
Jet Electrodeposition ◽  
Jet Velocity ◽  
Dendritic Structures

The bulk porous nickel was fabricated by layer scanning jet electrodeposition, a novel porous metal preparation technique. The dendritic crystalline layer or normal layer of the bulk porous nickel can be obtained by controlling of the growth conditions. The effects of deposition conditions, such as jet velocity, deposition current density, jet scanning mode, scanning rate, electrolyte solution, etc., on the morphology and growth process of the dendritic structures were studied in detail. It is revealed that the deposition rate and the uniformity of the pore distribution for the bulk porous Ni increase with the decrease of jet velocity. The depositing current density has an upper and lower limit. The dendritic structures are sensitive to the scanning rate, scanning mode, electrolyte solution. As a result, the optimized bulk porous nickels with controllable dendritic crystalline layered structure, pore size and porosity were fabricated by accurately controlling the growth conditions above.

The effect of electroplating current density on microstructure, corrosion, and wear behavior of Ni–P–W–TiO2 coating

2021 ◽  
Vol 112 (6) ◽  
pp. 474-485
Author(s):  
Sajjad Sadeghi ◽  
Hadi Ebrahimifar
Keyword(s):  
Wear Resistance ◽  
Corrosion Resistance ◽  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Current Density ◽  
Potentiodynamic Polarization ◽  
Electrochemical Impedance ◽  
Wear Behavior ◽  
Micro Hardness ◽  
Aisi 304L

Abstract The use of ceramic particles in the matrix of alloy coatings during the electroplating process has received considerable attention. These particles can create properties such as high corrosion resistance, insolubility, high-temperature stability, strong hardness, and self-lubrication capability. Herein, an Ni–P–W–TiO2 coating was deposited on an AISI 304L steel substrate using the electroplating method. Electroplating was performed at current densities of 10, 15, 20, and 25 mA · cm–2, and the effect of current density on microstructure, corrosion behavior, and wear behavior was investigated. The coatings were characterized by means of scanning electron microscopy. To investigate corrosion resistance, potentiodynamic polarization and electrochemical impedance spectroscopy tests were performed in a 3.5% NaCl aqueous solution. A pin-on-disk test was conducted to test the wear resistance of uncoated and coated samples. Sample micro-hardness was also measured by Vickers hardness testing. Examination of the microstructure revealed that the best coating was produced at a current density of 20 mA · cm–2. The results of potentiodynamic polarization and electrochemical impedance spectroscopy tests were consistent with microscopic images. The coating created at the current density of 20 mA · cm–2 had the highest corrosion resistance compared to other coated and non-coated samples. Furthermore, the results of the wear test showed that increasing the current density of the electroplating path up to 20 mA · cm–2 enhances micro-hardness and wear resistance.

scholarly journals Mechanical Behavior of Entangled Metallic Wire Materials under Quasi-Static and Impact Loading

Materials ◽  
2019 ◽  
Vol 12 (20) ◽  
pp. 3392 ◽  
Author(s):  
Yiwan Wu ◽  
Lei Jiang ◽  
Hongbai Bai ◽  
Chunhong Lu ◽  
Shangzhou Li
Keyword(s):  
Energy Absorption ◽  
Impact Loading ◽  
Absorption Rate ◽  
Maximum Load ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Metallic Wire ◽  
Maximum Deformation ◽  
Air Damping ◽  
Stiffness And Damping

In this paper, the stiffness and damping property of entangled metallic wire materials (EMWM) under quasi-static and low-velocity impact loading were investigated. The results reveal that the maximum deformation of the EMWM mainly depends on the maximum load it bears, and that air damping is the main way to dissipate impact energy. The EMWM can absorb more energy (energy absorption rate is over 60%) under impact conditions. The EMWM has excellent characteristics of repetitive energy absorption.

scholarly journals Development of Porous Pt Electrocatalysts for Oxygen Reduction and Evolution Reactions

Molecules ◽  
2020 ◽  
Vol 25 (10) ◽  
pp. 2398
Author(s):  
Marika Muto ◽  
Mayumi Nagayama ◽  
Kazunari Sasaki ◽  
Akari Hayashi
Keyword(s):  
Oxygen Reduction ◽  
Current Density ◽  
Polymer Electrolyte Membrane ◽  
Porous Metal ◽  
Pem Fuel Cells ◽  
Reduction Reaction ◽  
Electrolyte Membrane ◽  
Catalyst Layers ◽  
Pt Electrocatalysts ◽  
Pt Black

Porous Pt electrocatalysts have been developed as an example of carbon-free porous metal catalysts in anticipation of polymer electrolyte membrane (PEM) fuel cells and PEM water electrolyzers through the assembly of the metal precursor and surfactant. In this study, porous Pt was structurally evaluated and found to have a porous structure composed of connected Pt particles. The resulting specific electrochemical surface area (ECSA) of porous Pt was 12.4 m2 g−1, which was higher than that of commercially available Pt black. Accordingly, porous Pt showed higher oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) activity than Pt black. When the activity was compared to that of a common carbon-supported electrocatalyst, Pt/ketjen black (KB), porous Pt showed a comparable ORR current density (2.5 mA cm−2 at 0.9 V for Pt/KB and 2.1 mA cm−2 at 0.9 V for porous Pt), and OER current density (6.8 mA cm−2 at 1.8 V for Pt/KB and 7.0 mA cm−1 at 1.8 V), even though the ECSA of porous Pt was only one-sixth that of Pt/KB. Moreover, it exhibited a higher durability against 1.8 V. In addition, when catalyst layers were spray-printed on the Nafion® membrane, porous Pt displayed more uniform layers in comparison to Pt black, showing an advantage in its usage as a thin layer.

Effect of Current Density on the Composition and Mechanical Properties of Cr1-xAlxN Coating by Ion Arc Plating

2012 ◽  
Vol 557-559 ◽  
pp. 1971-1974
Author(s):  
Cheng Xi Wang ◽  
Ji Hua Peng ◽  
Xian Wen Liang ◽  
Jun Tian
Keyword(s):  
Mechanical Properties ◽  
Surface Morphology ◽  
Current Density ◽  
Adhesion Force ◽  
Atomic Ratio ◽  
Pure Metal ◽  
Metal Target ◽  
Micro Hardness ◽  
Al Content ◽  
Maximum Value

The Cr1-xAlxN coatings were deposited onto M2 tool steel using ion arc plating technique. The effect of current density on the surface morphology and mechanical properties of TiN/CrAlN coating was made. It was found that adjusting the pure metal target currents is not only to change the metal atomic ratio, but also to influence the surface morphology, their hardness and adhesion. The micro hardness Hv increases almost linearly with Al content of the coating in this study, and the Cr0.41Al0.59N coating reaches Hv 2950. The adhesion force between the coating and the substrate reaches maximum value 55N, when the [Al]/[Al+Cr] ratio is 0.44.

Preparation and Characterization of a Novel γ-PGA/β-Tricalcium Phosphate Composite for Tissue Engineering

2014 ◽  
Vol 900 ◽  
pp. 306-311 ◽  
Author(s):  
Xiu Lin Shu ◽  
Qing Shan Shi ◽  
Xiao Bao Xie ◽  
Xiao Mo Huang ◽  
Yi Ben Chen
Keyword(s):  
Tissue Engineering ◽  
Cell Growth ◽  
Porous Structure ◽  
Water Absorption ◽  
Tricalcium Phosphate ◽  
Absorption Rate ◽  
Swelling Ratio ◽  
Composite Scaffolds

In order to improvedβ-TCP biocompatibility and cell growth, was chosen to modify β-TCP matrices to produce a γ-PGA/β-TCP composite biomaterial. Then, the morphology, water uptake and retention abilities,in vitrodegradation property in the simulated medium, cytotoxicity of this novel γ-PGA/β-TCP composite is investigated. SEM shows that the γ-PGA/β-TCP composite has a porous structure. By increasing the percentage ofγ-PGA from 0% to 50%, the swelling ratio of the composite s was enhanced from 9.0%to 297%. These data suggested that the surface hydrophilicity, water absorption rate, and swelling ratio were improved by adding γ-PGA to the composite. In the cytocompatibility test, the density of MC3T3-E1 preosteoblasts cells on the PTCP1:1 leachates was almost 110% higher than that on the controls on day 3. Therefore, the γ-PGA/β-TCP composite scaffolds, due to their better hydrophilicity, cytocompatibility, and porous structure, are very promising biomaterials for tissure engineering applications.

scholarly journals Dynamics Analysis of Active Variable Stiffness Vibration Isolator for Whole-Spacecraft Systems Based on Nonlinear Output Frequency Response Functions

2020 ◽  
Vol 33 (6) ◽  
pp. 731-743
Author(s):  
Kefan Xu ◽  
Yewei Zhang ◽  
Yunpeng Zhu ◽  
Jian Zang ◽  
Liqun Chen
Keyword(s):  
Frequency Response ◽  
Energy Absorption ◽  
Absorption Rate ◽  
Vibration Isolation ◽  
Variable Stiffness ◽  
Response Functions ◽  
Vibration Isolator ◽  
Output Frequency ◽  
Frequency Response Functions ◽  
Vibration Transmissibility

AbstractIn order to improve the harsh dynamic environment experienced by heavy rockets during different external excitations, this study presents a novel active variable stiffness vibration isolator (AVS-VI) used as the vibration isolation device to reduce excessive vibration of the whole-spacecraft isolation system. The AVS-VI is composed of horizontal stiffness spring, positive stiffness spring, parallelogram linkage mechanism, piezoelectric actuator, acceleration sensor, viscoelastic damping, and PID active controller. Based on the AVS-VI, the generalized vibration transmissibility determined by the nonlinear output frequency response functions and the energy absorption rate is applied to analyze the isolation performance of the whole-spacecraft system with AVS-VI. The AVS-VI can conduct adaptive vibration suppression with variable stiffness to the whole-spacecraft system, and the analysis results indicate that the AVS-VI is effective in reducing the extravagant vibration of the whole-spacecraft system, where the vibration isolation is decreased up to above 65% under different acceleration excitations. Finally, different parameters of AVS-VI are considered to optimize the whole-spacecraft system based on the generalized vibration transmissibility and the energy absorption rate.

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