Adhesion Improvement of Nickel Electrodeposited on Aluminum Alloy 7075 by Modified Single Zincating Process

2016 ◽  
Vol 694 ◽  
pp. 143-150 ◽  
Author(s):  
Intan Sharhida Othman
Keyword(s):  
Electron Microscopy ◽  
Open Circuit Potential ◽  
Open Circuit ◽  
Transition Curve ◽  
Dense Layer ◽  
X Rays ◽  
Energy Dispersive Analysis ◽  
Electrodeposited Nickel ◽  
Aluminum Alloy 7075 ◽  
Scanning Electron

The time-transition curve of open circuit potential (Eoc) during the single zincating process of aluminium alloy 7075 (AA7075) was recorded. Then, a suitable single zincating duration was selected from the Eoc slope, in order to get the optimum zincating duration. The evolution of surface morphology and composition of AA7075 substrate at various single zincating durations were characterized by scanning electron microscopy (SEM) and energy dispersive analysis of x- rays (EDX). The coating adhesions of single zincated samples produced at various durations were investigated using a scratch tester. SEM results showed that the substrates produced at a longer zincating duration were fully covered by a dense layer of zinc particles. The adhesion of the electrodeposited nickel on single zincated samples produced at longer zincating duration was higher than the conventional single zincating process. This morphology has contributed to the improvement of coating adhesion.

Effect of Bi Addition on the Electrochemical Behavior of Zinc Electrodes in Concentrated Alkaline Solutions

2013 ◽  
Vol 805-806 ◽  
pp. 1240-1249
Author(s):  
Hong Xia Liang ◽  
Fu Rong Li ◽  
Zhi Lin Wang
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Linear Polarization ◽  
Electrochemical Behavior ◽  
Open Circuit Potential ◽  
Open Circuit ◽  
Exchange Current ◽  
Zinc Electrode ◽  
Current Densities ◽  
Scanning Electron

The electrochemical behavior of zinc electrode with bismuth addition in 35%KOH solutions has been investigated systematically by electrochemical methods including linear polarization, potentiostatic polarization, potential-time measurements at a constant current density, combining the observations of scanning electron microscopy (SEM). Linear polarization results showed that the open circuit potential shifted positively with increasing bismuth content, which is explained based on the gassing data and change in the exchange current of the zinc electrode. Addition of bismuth increased the exchange current of zinc reaction and caused an increase in the measured open circuit potential. Galvanostatic results showed that the addition of bismuth shortened the passivation time. Scanning electron microscopy images showed that the addition of bismuth aggravated the corrosion of zinc electrode which may be responsible for the increased tendency to passivation at high current densities. It has been found that at low current densities the reaction kinetics may be increased by addition of Bi, which is general agreement with the discharging test of actual alkaline batteries.

scholarly journals Understanding the Nature of the Manganese Hot Dip Phosphatizing Process of Steel

2017 ◽  
Vol 57 (4) ◽  
Author(s):  
Gabriela Alvarado-Macías ◽  
Juan Carlos Fuentes-Aceituno ◽  
Armando Salinas-Rodríguez ◽  
Francisco Javier Rodríguez-Varela
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Phosphoric Acid ◽  
Species Distribution ◽  
Open Circuit Potential ◽  
Open Circuit ◽  
The Other ◽  
Energy Dispersive ◽  
X Ray ◽  
Scanning Electron

In this work, the phosphatizing process of steel is investigated using open circuit potential and Tafel curves as well as scanning electron microscopy and energy dispersive X-ray spectroscopy. The results reveal that a pH of 2.57 in the phosphatizing solution promotes the dissociation of phosphoric acid which assists the formation of the manganese tertiary salt (Mn<sub>3</sub>(PO<sub>4</sub>)<sub>2</sub>), which is deposited on the substrate. It was also observed that an increase in the temperature from 25 to 90°C and the presence of HNO<sub>3</sub> as catalyst enhances the manganese phosphatizing kinetics. On the other hand, the generation of iron phosphates and oxides is predominant at a pH of 1 and 90°C. These observations are supported by species distribution and Pourbaix thermodynamic diagrams.

Fabrication and Photoresponse of Self-Organized TiO2 Mesoporous by Alternative Voltage Condition

2012 ◽  
Vol 626 ◽  
pp. 580-583
Author(s):  
Pacharee Krongkitsiri ◽  
Udom Tipparach
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Oxalic Acid ◽  
Open Circuit Potential ◽  
Pure Titanium ◽  
Open Circuit ◽  
Self Organized ◽  
Anodization Method ◽  
Scanning Electron

Mesoporous of TiO2electrodes (MOTE) were fabricated on pure titanium sheets in aqueous based electrolytes that consist of NaSO4NH4F and Oxalic acid by an anodization method with alternative voltage condition. Morphology of MOTE was characterized by scanning electron microscopy. The characteristic photoresponse in 0.1 M Na2SO4on the MOTE was investigated. The MOTE shows an excellent photoresponse property that is significant at low open-circuit potential.

Defects of Platelet Function Recognized by X-Ray Imaging and Scanning Electron Microscopy

1985 ◽  
Vol 43 ◽  
pp. 610-613
Author(s):  
M.G. Baldini ◽  
S. Morinaga ◽  
D. Minasian ◽  
R. Feder ◽  
D. Sayre ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Cell Biology ◽  
Imaging Technique ◽  
Human Platelets ◽  
X Rays ◽  
X Ray ◽  
X Ray Imaging ◽  
Complex Phenomena ◽  
Scanning Electron

Contact X-ray imaging is presently developing as an important imaging technique in cell biology. Our recent studies on human platelets have demonstrated that the cytoskeleton of these cells contains photondense structures which can preferentially be imaged by soft X-ray imaging. Our present research has dealt with platelet activation, i.e., the complex phenomena which precede platelet appregation and are associated with profound changes in platelet cytoskeleton. Human platelets suspended in plasma were used. Whole cell mounts were fixed and dehydrated, then exposed to a stationary source of soft X-rays as previously described. Developed replicas and respective grids were studied by scanning electron microscopy (SEM).

STUDY OF Y-Ba-Cu-O SUPERCONDUCTORS PREPARED WITH THE OXALATE PRECIPITATION/EVAPORATION METHOD

1990 ◽  
Vol 04 (19) ◽  
pp. 1237-1244 ◽  
Author(s):  
TH. LEVENTOURI ◽  
E. LIAROKAPIS ◽  
L. MARTINEZ ◽  
F.D. MEDINA ◽  
M. MORENO ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Raman Spectroscopy ◽  
Magnetic Measurements ◽  
Preparation Procedure ◽  
X Rays ◽  
Evaporation Method ◽  
Preparation Conditions ◽  
Oxalate Precipitation ◽  
Scanning Electron

A study is presented on a series of Y-Ba-Cu-O superconductors prepared with the Oxalate Precipitation/Evaporation method. The effect of the preparation conditions on the properties of these superconductors has been studied with X-rays, scanning electron microscopy, Raman spectroscopy, and magnetic measurements. The experiments show that good quality superconductors can be fabricated with this preparation procedure and also indicate that the properties of these materials are very sensitive to the preparation conditions.

Forming of Corrosion Inhibitor Film during Turbulent Flow

2011 ◽  
Vol 66-68 ◽  
pp. 540-544 ◽  
Author(s):  
Ahmed Y. Musa ◽  
Abdul Amir H. Kadhum ◽  
Abu Bakar Mohamad ◽  
Mohd Sobri Takriff
Keyword(s):  
Turbulent Flow ◽  
Potentiodynamic Polarization ◽  
Flow Condition ◽  
Open Circuit Potential ◽  
Electrochemical Impedance ◽  
Steel Corrosion ◽  
Film Structure ◽  
Open Circuit ◽  
Mild Steel Corrosion ◽  
Scanning Electron

The organic material named 4-amino-5-phenyl-4H-1, 2, 4-trizole-3-thiol (APTT) was studied as inhibitor for mild steel corrosion in 1.0 M HCl at 30 °C. The effects of turbulent flow on the inhibition process were characterized using open circuit potential (OCP), potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) and scanning electron microscopy (SEM). Turbulent flow condition experiments were simulated by Rotating Cylinder Electrode (RCE). Results obtained from changes of open circuit potential (OCP) with immersion time, potentiodynamic polarization, and impedance measurements all are in good agreement and indicated that the formation and the development of the inhibitor film were flow rate dependence. The scanning electron micrograph confirmed film structure is dependence of flow condition.

Phase Equilibria in the BaO-SiO2-Al2O3 Ternary System at 1500 °C

2016 ◽  
Vol 697 ◽  
pp. 565-571 ◽  
Author(s):  
Rui Zhang ◽  
Pekka Taskinen
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Ternary System ◽  
Phase Equilibria ◽  
Ternary Compound ◽  
Energy Dispersive Analysis ◽  
Liquidus Composition ◽  
Isothermal Sections ◽  
X Ray ◽  
Scanning Electron

Phase equilibria of the BaO-SiO2-Al2O3 ternary system was experimentally investigated using a quenching technique and analyzed by Scanning Electron Microscopy (SEM) equipped with Energy Dispersive Analysis (EDS) and X-ray Powder Diffraction (XRD). A ternary compound was confirmed in the present work. The liquidus composition in equilibrium with the ternary compound at 1500 °C were quantified. The isothermal sections of the BaO-SiO2-Al2O3 ternary system at 1400 °C, 1500 °C, 1600 °C, and 1700 °C were calculated. Based on the data acquired, the isothermal section at 1500 °C was constructed.

Synthesis and characterization of sodalite as matrix for conditioning chloride spent salts from pyroprocesses

2009 ◽  
Vol 1193 ◽  
Author(s):  
G. De Angelis ◽  
I. Bardez-Giboire ◽  
M. Mariani ◽  
M. Capone ◽  
M. Chartier ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Sodium Aluminate ◽  
Argon Atmosphere ◽  
Synthesis And Characterization ◽  
Chloride Salt ◽  
X Rays ◽  
Density Measurements ◽  
Quality Product ◽  
Scanning Electron

AbstractTwo different methods have been used to synthesize sodalite for conditioning of chloride salt wastes coming from pyroprocesses: the first one, starting from kaolinite through the intermediate nepheline phase; the second one, starting from silica and sodium aluminate reagents, directly. The obtained products have been characterized by means of several analyses. In particular, different instrumental techniques – stereomicroscopy, scanning electron microscopy (SEMEDS), density measurements, thermogravimetric analysis, X-rays diffraction, FTIR spectroscopy – were performed revealing that the synthesis from kaolinite is the best method, provided that rigorous conditions are followed. The use of an argon atmosphere for the preparation of pellets of reagents is strictly necessary for the obtainment of a good quality product.

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