scholarly journals Effects of Pulse Electroplating Parameters on Return Loss (S11) and Surface Roughness of Silver Coatings

2019 ◽  
Author(s):  
Caner BASARAN ◽  
ishak karakaya
Keyword(s):  
Surface Roughness ◽  
Electromagnetic Waves ◽  
Return Loss ◽  
Electrochemical Engineering ◽  
Average Current Density ◽  
Cycle Frequency ◽  
Microwave Frequencies ◽  
Pulse Electroplating ◽  
Gold Plate ◽  
Average Current

The highly conductive silver is widely used in the electronics industry, especially in microwave systems [1]. A silver-plated part will reduce loss at the highest microwave frequencies. In addition to this, it will carry extremely high current load. Surface roughness which distorts the propagation of electromagnetic waves is known to affect the uniformity of the current distribution of very good conductive metals such as silver [1]. The effects of duty cycle, frequency and average current density, which are pulsed silver-plating parameters, on the surface quality of coating have been investigated in this study. These effects have been examined by comparing the return loss (S11). S11 comparisons were made according to a reference gold plate. When S11 comparisons have been made, increasing return loss appears with increasing surface roughness. These effects have been characterized by SEM and XRD. [1] Balanis, C. A. (1989). Advanced Engineering Electromagnetics. John Wiley & Son 235th ECS Meeting Session: Industrial Electrochemistry and Electrochemical Engineering Division General Session 1Symposium: F01 - Industrial Electrochemistry and Electrochemical Engineering General SessionTechnical Interest Area: F - Electrochemical EngineeringDay: Wednesday, 29 May 2019

scholarly journals The study of Zn–Co alloy coatings electrochemically deposited by pulse current

2012 ◽  
Vol 66 (5) ◽  
pp. 749-757 ◽  
Author(s):  
Jelena Bajat ◽  
Miodrag Maksimovic ◽  
Milorad Tomic ◽  
Miomir Pavlovic
Keyword(s):  
Surface Roughness ◽  
Current Efficiency ◽  
Direct Current ◽  
Current Density ◽  
Pulse Current ◽  
Pulse Plating ◽  
Cathodic Current ◽  
Average Current Density ◽  
Corrosion Stability ◽  
Average Current

The electrochemical deposition by pulse current of Zn-Co alloy coatings on steel was examined, with the aim to find out whether pulse plating could produce alloys that could offer a better corrosion protection. The influence of on-time and the average current density on the cathodic current efficiency, coating morphology, surface roughness and corrosion stability in 3% NaCl was examined. At the same Ton/Toff ratio the current efficiency was insignificantly smaller for deposition at higher average current density. It was shown that, depending on the on-time, pulse plating could produce more homogenous alloy coatings with finer morphology, as compared to deposits obtained by direct current. The surface roughness was the greatest for Zn-Co alloy coatings deposited with direct current, as compared with alloy coatings deposited with pulse current, for both examined average current densities. It was also shown that Zn-Co alloy coatings deposited by pulse current could increase the corrosion stability of Zn-Co alloy coatings on steel. Namely, alloy coatings deposited with pulse current showed higher corrosion stability, as compared with alloy coatings deposited with direct current, for almost all examined cathodic times, Ton. Alloy coatings deposited at higher average current density showed greater corrosion stability as compared with coatings deposited by pulse current at smaller average current density. It was shown that deposits obtained with pulse current and cathodic time of 10 ms had the poorest corrosion stability, for both investigated average deposition current density. Among all investigated alloy coatings the highest corrosion stability was obtained for Zn-Co alloy coatings deposited with pulsed current at higher average current density (jav = 4 A dm-2).

Effect of Ultrasonic Electroforming Process Parameters on Reflective Performance of Nickel Casting Layer

2014 ◽  
Vol 488-489 ◽  
pp. 222-227
Author(s):  
Fei Ye ◽  
Guang Yang ◽  
Jun Pi ◽  
Zi Qian Chen
Keyword(s):  
Surface Roughness ◽  
Process Parameters ◽  
Current Density ◽  
Laser Scanning ◽  
Laser Scanning Microscopy ◽  
Ultrasonic Power ◽  
Experimental Conditions ◽  
Average Current Density ◽  
Electroforming Process ◽  
Average Current

In order to improve the reflection coefficient of nickel electroforming layer with microprism structure effectively, controlling electroforming process strictly and adjusting different process parameters are needed for achieve the best electroforming effect. Nickel casting layer was prepared by ultrasonic direct current electroforming on the microprism nickel plate. Surface reflective coefficient of nickel casting layer was measured by retroreflectometer, and the morphology was observed by 3D laser scanning microscopy system. The effects of ultrasonic power, frequency and average current density on the surface reflective performance were studied, experimental results were verified by measuring microprism side surface roughness. The results show that reflective coefficient of nickel casting layer prepared by high frequency ultrasonic electroforming was greater than that by low frequency with other experimental conditions remaining unchanged. It was increased first and then decreased with ultrasonic power and average current density increasing gradually, and the surface roughness measurement also verified this conclusion.

Effects of Process on Electrochemical Properties of Pulse Electrodeposited Ti/Pb-WC-PANI Inert Electrodes

2011 ◽  
Vol 311-313 ◽  
pp. 223-226
Author(s):  
Mei Mei Wang ◽  
Mei Cao ◽  
Zhong Cheng Guo
Keyword(s):  
Current Density ◽  
Bath Temperature ◽  
Solid Particles ◽  
Process Conditions ◽  
Optimal Process ◽  
Pulse Period ◽  
Average Current Density ◽  
Pulse Electroplating ◽  
Average Current ◽  
Pulse On Time

Ti/Pb-WC-PANI inert electrodes was prepared by pulse electroplating. The effects of process conditions and concentration of solid particles on kinetic parameters of oxygen evolution, appearance of coating and deposition rate was studied and the process of electroplating was optimized. The optimal process conditions were as follows: PANI 30 g/L, WC 40 g/L, pulse on-time 0.5 ms, pulse period 1.5 ms, average current density 2 A•dm-2, bath temperature 25 °C.

Electrolytic Isolation of Twin-Type Shock Deformation Structures

1967 ◽  
Vol 25 ◽  
pp. 318-319
Author(s):  
F. I. Grace ◽  
L. E. Murr
Keyword(s):  
Grain Boundaries ◽  
Thin Foil ◽  
Electrolyte Composition ◽  
Experimental Conditions ◽  
Average Current Density ◽  
Electron Transmission ◽  
Deformation Structures ◽  
The Matrix ◽  
Average Current ◽  
Specimen Edge

During the course of electron transmission investigations of the deformation structures associated with shock-loaded thin foil specimens of 70/30 brass, it was observed that in a number of instances preferential etching occurred along grain boundaries; and that the degree of etching appeared to depend upon the various experimental conditions prevailing during electropolishing. These included the electrolyte composition, the average current density, and the temperature in the vicinity of the specimen. In the specific case of 70/30 brass shock-loaded at pressures in the range 200-400 kilobars, the predominant mode of deformation was observed to be twin-type faults which in several cases exhibited preferential etching similar to that observed along grain boundaries. A novel feature of this particular phenomenon was that in certain cases, especially for twins located in the vicinity of the specimen edge, the etching or preferential electropolishing literally isolated these structures from the matrix.

scholarly journals Application of the Composite Hardness Models in the Analysis of Mechanical Characteristics of Electrolytically Deposited Copper Coatings: The Effect of the Type of Substrate

Metals ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 111
Author(s):  
Ivana O. Mladenović ◽  
Nebojša D. Nikolić ◽  
Jelena S. Lamovec ◽  
Dana Vasiljević-Radović ◽  
Vesna Radojević
Keyword(s):  
Mechanical Characteristics ◽  
Dislocation Creep ◽  
Average Current Density ◽  
Fine Grained ◽  
Copper Coatings ◽  
Electrochemically Deposited ◽  
Composite Models ◽  
Average Current ◽  
Composite Hardness ◽  
Coating Hardness

The mechanical characteristics of electrochemically deposited copper coatings have been examined by application of two hardness composite models: the Chicot-Lesage (C-L) and the Cheng-Gao (C-G) models. The 10, 20, 40 and 60 µm thick fine-grained Cu coatings were electrodeposited on the brass by the regime of pulsating current (PC) at an average current density of 50 mA cm−2, and were characterized by scanning electron (SEM), atomic force (AFM) and optical (OM) microscopes. By application of the C-L model we determined a limiting relative indentation depth (RID) value that separates the area of the coating hardness from that with a strong effect of the substrate on the measured composite hardness. The coating hardness values in the 0.9418–1.1399 GPa range, obtained by the C-G model, confirmed the assumption that the Cu coatings on the brass belongs to the “soft film on hard substrate” composite hardness system. The obtained stress exponents in the 4.35–7.69 range at an applied load of 0.49 N indicated that the dominant creep mechanism is the dislocation creep and the dislocation climb. The obtained mechanical characteristics were compared with those recently obtained on the Si(111) substrate, and the effects of substrate characteristics such as hardness and roughness on the mechanical characteristics of the electrodeposited Cu coatings were discussed and explained.

The efficient use of stabilizing materials in superconducting solenoids

1969 ◽  
Vol 47 (13) ◽  
pp. 1401-1407 ◽  
Author(s):  
Richard Stevenson
Keyword(s):  
Current Density ◽  
Transient Heat Conduction ◽  
Point Of View ◽  
Average Current Density ◽  
Initial Current ◽  
Current Sharing ◽  
Purity Aluminium ◽  
High Purity Aluminium ◽  
Average Current ◽  
Composite Conductor

The problem of stability of superconducting solenoids is considered from a thermal point of view. The transient heat conduction equation for a superconducting tape clad with normal material and operated in a current sharing mode is studied, and a solution for the temperature distribution is obtained. The composite conductor is considered stable if its final temperature in the current sharing mode corresponds to the critical temperature for the initial current density in the superconductor. Using this criterion, the operating point of the superconductor and its stabilizing cladding thickness can be chosen to give a maximum average current density in the composite conductor at any field. Calculations are given for Nb3Sn tape clad with OFHC copper and with high purity aluminium.

Study on the Influence of Electrode Collocation to Electric Field Characteristic of ESP

2014 ◽  
Vol 875-877 ◽  
pp. 1683-1686
Author(s):  
Cheng Liang Jia ◽  
You Shan Sun ◽  
Chao Huang ◽  
Wan Peng Zhang ◽  
Fang Chen
Keyword(s):  
Electric Field ◽  
Current Density ◽  
Surface Current ◽  
Electrode Configuration ◽  
Electrode Gap ◽  
Average Current Density ◽  
Surface Current Density ◽  
Discharge Electrode ◽  
Field Characteristic ◽  
Average Current

A laboratory-scale ESP with new electrode configuration was established to investigate the electric field characteristic. Eight teeth prick line and prick plate with the length of 20mm were employed as discharge electrodes, respectively. The effects of discharge electrode type and electrode gap on V-I characteristic and surface current density were studied. The results showed that the optimum electrode gaps were 350-400mm for eight teeth line and 300-350mm for prick plate, which could obtained higher average current density and lower variance.

Analysis of Performance and Thermal-Fluid Characteristics in a Planar Type Solid Oxide Fuel Cell

2012 ◽  
Vol 9 (3) ◽  
Author(s):  
Hyojung Ahn
Keyword(s):  
Gas Flow ◽  
Solid Oxide ◽  
Utilization Rate ◽  
Ceramic Plate ◽  
Oxide Fuel ◽  
Average Current Density ◽  
Operation Temperature ◽  
Effective Combination ◽  
Average Current ◽  
Gas Supply

This work studied internal loss factors (flow rate, pressure, partial pressure, voltage, current, temperature, etc.) in a unit cell and stack of solid oxide fuel cells (SOFC) with different separator materials, operation temperature and types of gas supply channels by employing computational fluid dynamics (CFD). A steel separator (AISI430) was superior to a ceramic plate (LaCrO3) in an aspect of thermal stress due to high thermal conductivity but inferior at average current density and fuel utilization rate. As initial temperature at the cell inlet was lowered from 950 °C to 650 °C per each pattern of gas flow (co-flow and counter-flow), useful data were acquired to analyze a performance drop. I-V curves at 650 °C and 900 °C, which involved various parameters as separator materials and directions of gas supply, compared performance characterization between low and high temperature SOFC and also implied the most effective combination.

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