A Study on the Hydrogen Evolving Activity of Electroplated Ni-P Coating by Using the Taguchi Method

2011 ◽  
Vol 14 (4) ◽  
pp. 237-245 ◽  
Author(s):  
Hung-Bin Lee ◽  
Chen-Hsiung Hsu ◽  
Dong-Sing Wuu
Keyword(s):  
Grain Size ◽  
Internal Stress ◽  
Process Parameters ◽  
Current Density ◽  
Duty Cycle ◽  
Phosphorous Acid ◽  
Taguchi’S Method ◽  
P Content ◽  
The One ◽  
High Internal Stress

The optimal catalytic activity of the electrodeposited Ni-P coating with the control of the process parameters was performed in this study by using Taguchi’s method. The controlled process parameters included current density, duty cycle and the concentration of the phosphorous acid in the electrolyte. The correlation among the controlled parameters and the resulted hydrogen evolution reaction (HER) activity was discussed with emphasis on the influence of the P content, internal stress, roughness and grain size of the coating. The optimal HER property was obtained for the electrodeposition of Ni-P coating with a phosphorous acid concentration of 5g/l, current density of 16A/dm2 and duty cycle of 100 %. The resulted Ni-P coating with a better HER property was the one with P content 3at%, an internal stress higher than 10MPa, grain size 10~15nm and surface roughness higher than 100nm. In addition, the cracking of the coating due to high internal stress favored the raise of the HER activity.

Study on Wear-Resisting Property of Nickel-Diamond Composite Electroforming Films in Supercritical Fluids

2015 ◽  
Vol 778 ◽  
pp. 174-178
Author(s):  
Hai Feng Qian ◽  
Wei Ning Lei ◽  
Mi Qian ◽  
Wei Qiao Liu ◽  
Chuang Ye Wang
Keyword(s):  
Internal Stress ◽  
Supercritical Fluids ◽  
Process Parameters ◽  
Current Density ◽  
Sectional Area ◽  
Working Pressure ◽  
Cross Sectional ◽  
Diamond Composite ◽  
Spherical Crystallization ◽  
Orthogonal Tests

Ni-diamond nanocomposite electroforming films were prepared in supercritical fluids. The effect of process parameters to wear-resisting property of composite electroforming films was analyzed by orthogonal tests, which included current density, working time, diamond content and working pressure. It has been found that the composite electroforming films prepared in supercritical CO2 fluids have spherical crystallization with refined crystalline grain and small internal stress. Then it can be that the wear-resisting property of supercritical electroforming films is far higher than that of conventional electroforming by detecting the wear scar cross-sectional area, and the wear-resisting property increased by 18.8%.

Optimization of Process Parameters of Ni-TiN-CeO2 Binary Nanocomposite Coatings by Ultrasound-Pulse Electrodeposition

2012 ◽  
Vol 217-219 ◽  
pp. 1331-1335
Author(s):  
Na Na Liu ◽  
Meng Hua Wu ◽  
Zhi Li
Keyword(s):  
Process Parameters ◽  
Current Density ◽  
Duty Cycle ◽  
Steel Substrate ◽  
Cathode Current Density ◽  
Pulse Electrodeposition ◽  
Nanocomposite Coatings ◽  
Ultrasonic Power ◽  
Cathode Current ◽  
Ultrasound Pulse

Ni-TiN-CeO2 nanocomposite coatings on 45 steel substrate were prepared by ultrasound-pulse electrodeposition. The effects of process parameters, such as CeO2 and TiN nanoparticles addition, cathode current density, positive pulse duty cycle and ultrasonic power on the Ni-TiN-CeO2 nanocomposite electrodeposition process were studied by orthogonal experiments. The nanoparticles contents in the coating were determined, and the surface morphology of the coating was analyzed. The results show that the optimized process parameters are: the CeO2 particles addition of 40g/l, the TiN particles addition of 15g/l, cathode current density of 4A/dm2, positive duty cycle of 20%, and the ultrasonic power of 180W. Under the optimum condition, the desirable Ni-TiN-CeO2 nanocomposite coatings are prepared with higher particle content and better surface quality.

A Study of the Microstructure and Properties of Electroformed Ni-P Model Insert

2007 ◽  
Vol 364-366 ◽  
pp. 232-236 ◽  
Author(s):  
Shih Tsung Ke ◽  
Jeou Long Lee ◽  
Yih Min Yeh ◽  
Shuo Jen Lee ◽  
Ming Der Ger
Keyword(s):  
Internal Stress ◽  
Current Density ◽  
Duty Cycle ◽  
Pulse Current ◽  
Pulse Frequency ◽  
Cathodic Current ◽  
Peak Current Density ◽  
Peak Current ◽  
Ultrafine Grained ◽  
Nanostructure Material

In this study, a Ni-P alloy electroforming nanostructure material with low surface roughness and low internal stress was developed by using a pulse current. Square-wave cathodic current modulation was employed to electrodeposit ultrafine-grained Ni-P films from an additivefree Sulfamate nickel bath. The effect of various factors, such as peak current density, duty cycle and pulse frequency on the roughness and internal stress were investigated. Pulse current significantly influences the microstructure of Ni-P alloys. The internal stress and roughness of Ni-P alloys increased as peak current density increased, but the internal stress of Ni-P alloys decreased as duty cycle decreased.

Effect of current density on the deposit stress in gold electroplating

2017 ◽  
Vol 31 (17) ◽  
pp. 1750188
Author(s):  
Shuangyue Hou ◽  
Ying Xiong ◽  
Shan Chen ◽  
Xiangyu Chen ◽  
Penghui Xiong ◽  
...  
Keyword(s):  
Internal Stress ◽  
Current Density ◽  
Substrate Material ◽  
Gold Deposits ◽  
X Ray Diffraction ◽  
Contrast Imaging ◽  
X Ray ◽  
Critical Issues ◽  
Surface Morphologies ◽  
High Internal Stress

As the key components of grating-based X-ray phase contrast imaging, absorption gratings are essential to be fabricated. In fact, the internal stress is one of the critical issues for the application of the electroplated gold deposit as the absorption metal for absorption gratings. It is common that high internal stress levels can cause the deposit cracking, blistering and peeling away from the substrate material. This study investigates the effect of current density on the internal stress by the bent strip method. The surface morphologies of gold deposits are examined using scanning electron microscopy (SEM) and the crystal structure of the electroplated deposit is analyzed by X-ray diffraction (XRD). The change of current density reverses the internal stress of the deposits from compressive to tensile. The value of deposit stress can be near zero by optimizing the current density.

Study on Internal Stress in Micro-Electroformed Layer

2015 ◽  
Vol 645-646 ◽  
pp. 178-183 ◽  
Author(s):  
Li Qun Du ◽  
Zhi Cheng Tan ◽  
Chang Song ◽  
Zhong Zhao ◽  
Qing Feng Li ◽  
...  
Keyword(s):  
Internal Stress ◽  
Compressive Stress ◽  
Current Density ◽  
Stress Reduction ◽  
Research Work ◽  
Ultrasonic Power ◽  
Free Solution ◽  
And Performance ◽  
Additive Solution ◽  
High Internal Stress

Micro electroforming technology is widely used in fabrication of multilayer or moveable metal micro devices. The fabrication of these devices is usually suffered from high internal stress in micro-electroformed layers which seriously restricts the application and development of micro electroforming technology. Therefore, to control the internal stress is very important for improving the quality and performance of micro-electroformed layer. However, published studies on internal stress in the electroforming layer were mostly based on additive-free solution. According to additive solution, the effect of ultrasonic and current density on compressive stress occurring in the electroforming layer is investigated in this paper. The results indicate that the compressive stress keeps increasing with current density within range from 0.2 to 2 A/dm2. Meanwhile, the compressive stress in ultrasonic solution decreases by 73.4 MPa averagely comparing to that in ultrasonic-free solution, and the compressive stress also keeps decreasing with the ultrasonic power which gets the lowest value at 200W. Moreover, the mechanisms of additive-induced compressive stress and ultrasonic relieving compressive stress are discussed. This research work will complement the ultrasonic-stress reduction theory and may contribute to the development of micro electroforming technology.

scholarly journals Effects of Flash Sintering Parameters on Performance of Ceramic Insulator

Energies ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 1157
Author(s):  
Yong Liu ◽  
Xingwang Huang
Keyword(s):  
Grain Size ◽  
Electric Field ◽  
Field Intensity ◽  
Current Density ◽  
Electric Field Intensity ◽  
Unit Cell ◽  
Uniform Structure ◽  
Ceramic Insulator ◽  
Flash Sintering ◽  
Ceramic Insulators

Ceramic outdoor insulators play an important role in electrical insulation and mechanical support because of good chemical and thermal stability, which have been widely used in power systems. However, the brittleness and surface discharge of ceramic material greatly limit the application of ceramic insulators. From the perspective of sintering technology, flash sintering technology is used to improve the performance of ceramic insulators. In this paper, the simulation model of producing the ceramic insulator by the flash sintering technology was set up. Material Studio was used to study the influence of electric field intensity and temperature on the alumina unit cell. COMSOL was used to study the influence of electric field intensity and current density on sintering speed, density and grain size. Obtained results showed that under high temperature and high voltage, the volume of the unit cell becomes smaller and the atoms are arranged more closely. The increase of current density can result in higher ceramic density and larger grain size. With the electric field intensity increasing, incubation time shows a decreasing tendency and energy consumption is reduced. Ceramic insulators with a higher uniform structure and a smaller grain size can show better dielectric performance and higher flashover voltage.

scholarly journals Impact of Process Parameters on the Diameter of Nanobubbles Generated by Electrolysis on Platinum-Coated Titanium Electrodes Using Box–Behnken Experimental Design

Energies ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2542
Author(s):  
Karol Ulatowski ◽  
Radosław Jeżak ◽  
Paweł Sobieszuk
Keyword(s):  
Experimental Design ◽  
Process Parameters ◽  
Current Density ◽  
Salt Concentration ◽  
Multivariate Regression ◽  
Electrical Energy ◽  
Multiphase System ◽  
Anova Analysis ◽  
Dependent Variables ◽  
Parameter Function

(1) The generation of nanobubbles by electrolysis is an interesting method of using electrical energy to form bubble nuclei, effectively creating a multiphase system. For every process, the effectiveness of nanobubble generation by electrolysis depends on various process parameters that impact should be determined. (2) In this work, the electrolytic generation of hydrogen and oxygen bubbles was performed in a self-built setup, in which a Nafion membrane separated two chambers. The generation of bubbles of both gases was investigated using Box–Behnken experimental design. Three independent variables were salt concentration, current density, and electrolysis time, while the dependent variables were Sauter diameters of generated bubbles. An ANOVA analysis and multivariate regression were carried out to propose a statistical and power model of nanobubble size as a process parameter function. (3) The generation of bubbles of hydrogen and oxygen by electrolysis showed that different factors or their combinations determine their size. The results presented in this work proved to be complementary to previous works reported in the literature. (4) The Sauter diameter of bubbles increases with salt concentration and stays constant with increasing current density in investigated range. The proposed correlations allow the Sauter diameters of nanobubbles generated during electrolysis to be predicted.

scholarly journals Electrochemical synthesis of biobased polymers and polymer building blocks from vanillin

RSC Advances ◽  
2021 ◽  
Vol 11 (15) ◽  
pp. 8970-8985
Author(s):  
Robin Kunkel ◽  
Volkmar M. Schmidt ◽  
Carsten Cremers ◽  
Dominik Müller ◽  
Detlef Schmiedl ◽  
...  
Keyword(s):  
Process Parameters ◽  
Current Density ◽  
Electrode Material ◽  
Electrochemical Synthesis ◽  
Building Blocks ◽  
Biobased Polymers ◽  
The Impact

Hydrovanilloin and polyvanillin were synthesized electrochemically investigating the impact of process parameters such as electrode material, charge and current density.

Study on Electrodeposition of Ni-Graphite Composite Coatings in Sulfamate Bath

2010 ◽  
Vol 150-151 ◽  
pp. 1546-1550 ◽  
Author(s):  
Xiang Zhu He ◽  
Xiao Wei Zhang ◽  
Xin Li Zhou ◽  
Zhi Hong Fu
Keyword(s):  
Surface Morphology ◽  
Process Parameters ◽  
Current Density ◽  
Graphite Particle ◽  
Particle Concentration ◽  
Composite Coatings ◽  
Nickel Matrix ◽  
Graphite Composite ◽  
Surface Morphologies ◽  
Sulfamate Bath

This paper presented the composite coatings of nickel with graphite particle on the aluminum substrate using a nickel sulfamate bath. Effects of graphite particle concentration on the surface morphologies of the composite coatings were investigated. The inclusion of graphite particle into metal deposits was dependent on many process parameters, including particle concentration, current density, pH and temperature. Results of SEM and XRD demonstrated that graphite particle had successfully deposited on that nickel matrix; besides, the surface morphology of coatings obtained from sulfamate bath containing 2g/L graphite particle dispersed more uniformly than the ones with higher concentration.

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