Electrical discharge characteristics of a dielectric liquid under external flow in a microchannel with planar electrode configuration

2017 ◽  
Vol 87 ◽  
pp. 212-216
Author(s):  
M.K. Russel ◽  
P.R. Selvaganapathy ◽  
C.Y. Ching
Keyword(s):  
Electrical Discharge ◽  
External Flow ◽  
Dielectric Liquid ◽  
Electrode Configuration ◽  
Discharge Characteristics ◽  
Planar Electrode

Ti-6Al-4V Surfaces in SiC Powder Mixed Electrical Discharge Machining

2013 ◽  
Vol 856 ◽  
pp. 226-230 ◽  
Author(s):  
Hamidullah Yaşar ◽  
Bülent Ekmekci
Keyword(s):  
Electrical Discharge ◽  
Electrical Discharge Machining ◽  
Dielectric Liquid ◽  
Operational Parameters ◽  
Electrical Parameters ◽  
Machined Surface ◽  
Optical Scanning ◽  
Surface Topographies ◽  
Powder Suspension

The role of suspended particles on Ti-6Al-4V surface in Powder Mixed Electrical Discharge Machining (PMEDM) is studied using SiC powder mixing in water dielectric liquid. Surface modifications due to the additives in dielectric liquid are investigated by means of optical, scanning electron microscopy and energy dispersive spectroscopy. The attachment of added powders and surface topographies interrelated with powder suspension concentration, particle size and electrical parameters such as pulse on duration and current. The influence on discharge transitivity with respect to SiC additives is noticed with pock like features on the surface. The geometry and size of these features indicated a robust dependency with respect to operational parameters and indicated the role of secondary discharges during PMEDM. SiC particles severely transferred from di-electric liquid to machined surface at critical operational parameters and implied that the process could be also used as a surface alloying technique.

Electrical Characteristics of Chemical Solution Deposited Nd3+ Doped PZT (53/47) Thin Films in Planar Electrode Configuration

2000 ◽  
Vol 655 ◽  
Author(s):  
S.B. Majumder ◽  
B. Perez ◽  
B. Roy ◽  
A. Martinez ◽  
R.S. Katiyar
Keyword(s):  
Thin Films ◽  
Ferroelectric Properties ◽  
Hysteresis Loops ◽  
Electrode Configuration ◽  
Electrical Characteristics ◽  
Chemical Solution ◽  
Solution Deposition ◽  
Planar Electrode ◽  
Pzt Films ◽  
Formation Behavior

AbstractElectrical characteristics of ferroelectric thin films in planar electrode configuration are important to characterize these materials for their applications in micro electro mechanical (MEM) and tunable microwave devices. In the present work we have prepared polycrystalline Pb1划3x/2Ndx(Zr0.53Ti0.47)O3 (x = 0.0 to 10.0 at %) thin films on platinized silicon substrate by chemical solution deposition (CSD) technique. The films were characterized in terms of their dielectric and ferroelectric properties by depositing planar interdigital finger electrodes on the surface of the films by electron beam lithography. The capacitance and loss tangent of undoped and 4 at % Nd doped PZT films measured at 100 kHz were found to be 138 pF, 0.033 and 95 pF, 0.019 respectively. Saturated hysteresis loops were obtained in undoped PZT film by applying 100 V across 10 μm electrode separation. Nd doped PZT films on the other hand, electrically shorted at comparatively lower voltage. The electrical characteristics of these films are correlated with their phase formation behavior and microstructural features.

Numerical Simulation of Electrical Discharge Characteristics Induced by Underwater Wire Explosion

2018 ◽  
Vol 910 ◽  
pp. 72-77
Author(s):  
Ryo Henzan ◽  
Yoshikazu Higa ◽  
Osamu Higa ◽  
Ken Shimojima ◽  
Shigeru Itoh
Keyword(s):  
Numerical Simulation ◽  
Shock Wave ◽  
Electrical Discharge ◽  
Electrical Energy ◽  
Underwater Shock Wave ◽  
Discharge Characteristics ◽  
Wire Explosion ◽  
Electrical Wire ◽  
Electrical Wire Explosion ◽  
Underwater Shock

The underwater shock-wave phenomenon has been applied in various fields such as manufacturing and food processing and was investigated using many experimental and numerical analyses in the past. An underwater shock-wave is produced by various methods, e.g., underwater wire explosion and pulse-gap electrical discharge. Therefore, clarifying the shock characteristics depending on the stored electrical energy, wire dimension and material is extremely important. However, predicting the pressure and its distribution induced by underwater electrical wire explosion is hard because the phenomena associated with an elementary process are significantly complicated. In this study, to predict the discharge characteristics induced by underwater electrical wire explosion, numerical simulation based on the “simplified model of underwater electrical discharge” was performed. The numerical results show good agreement with the experimental ones.

Electrical Discharge Characteristics Using a Bubble in Water and Their Applications to the Water Treatment

2010 ◽  
Vol 13 (1) ◽  
Author(s):  
Chobei Yamabe ◽  
Satoshi Ihara
Keyword(s):  
Water Treatment ◽  
Breakdown Voltage ◽  
Applied Voltage ◽  
Electrical Discharge ◽  
Bubble Surface ◽  
Single Bubble ◽  
Discharge Characteristics ◽  
Treated Water ◽  
Direct Penetration

AbstractThe discharge in the single bubble that was introduced or fixed between the main electrodes was carried out and the electrical discharge characteristics in water were measured. The time-integrated photographs confirmed both the discharge along the bubble surface and the direct penetration in a bubble. The onset breakdown voltage increased gradually with the conductivity of treated water in range of 1.0 ~ 22.0 [ μ S/cm]. The onset breakdown voltage also increased with the steepness of the applied voltage dv/dt.

A Discharge Separation Model for Powder Mixed Electrical Discharge Machining

2016 ◽  
Vol 138 (8) ◽  
Author(s):  
Bülent Ekmekci ◽  
Hamidullah Yaşar ◽  
Nihal Ekmekci
Keyword(s):  
Electrical Discharge ◽  
Discharge Channel ◽  
Electrical Discharge Machining ◽  
Complete Separation ◽  
Dielectric Liquid ◽  
Material Transfer ◽  
Machined Surface ◽  
Machining Conditions ◽  
Main Discharge ◽  
Pulse On Time

Added powders in a dielectric medium substantially influence the features of electrical discharges due to altered interelectrode conditions during the electrical discharge machining (EDM) process. The main discharge channel is disturbed due to the added powders in dielectric liquid and leads formations of secondary discharges. Such altered discharge conditions generate a unique topography on the machined surface and consequent subsurface microstructure beneath it. Ti6Al4V work material machined using SiC powder mixing in de-ionized water for an extensive set of pulse-on duration and pulse currents. Then, different forms of secondary discharges were identified from the resultant surface features and corresponding subsurface microstructures. The results pointed out that generation of unevenly separated secondary discharges increased the material transfer rate from the powder mixed dielectric liquid to the machined surface by means of the decomposed ions in the plasma channel. Complete separation of the main discharge channel into evenly distributed secondary discharges is possible under specific machining conditions that suggested minimal deformation of the machined surface regarding microcracks, roughness, and heat affected layer thickness. Under such machining conditions, another means of material transfer mechanism is activated that lead a powder particle build-up process on the machined surface. Consequently, five different discharge forms were proposed to describe the resultant surface topographies and subsurface microstructures. The material migration phenomena and the mechanisms are discussed in relation to the pulse-on time and pulse current.

Research on discharge characteristics of working mediums of electric discharge machining

2020 ◽  
Vol 235 (1-2) ◽  
pp. 34-40
Author(s):  
Min Li ◽  
Lanrong Cai ◽  
Junling Zhao
Keyword(s):  
Electrical Discharge ◽  
Electrical Discharge Machining ◽  
Base Material ◽  
Deionized Water ◽  
Water Medium ◽  
Discharge Process ◽  
Dry Powder ◽  
Discharge Characteristics ◽  
Mixed Medium ◽  
Tc4 Alloy

Successful surface modification can be obtained by Electrical Discharge Machining (EDM). In this work the discharge characteristics in misted deionized water and near-dry powder-mixed medium was studied systematically, as well as the microstructure and properties of electrical discharge strengthened layers on TC4 alloy. It indicates that the breakdown voltage of EDM in misted deionized water medium has been reduced to about 1/3 than in air medium. In near-dry powder-mixed medium, it is reduced to about 1/9, because the discharge gap is much larger than that of other mediums. In other words, a stable discharge can be obtained by larger discharge gaps and lower pulse energy than traditional EDM surface strengthening method, which leads to more stable discharge process. Experimental researches show that dense and sound combination with matrix like, multiphase hybrid intensification and chrysanthemum petal-like microstructure of strengthened layers can be observed in the near-dry powder-mixed medium. Meanwhile, it is found that the microhardness of the strengthened layer is up to about 1200 HV, which is four times higher than the base material.

The Reactive Deposition of TiOx Thin Films

2014 ◽  
Vol 1040 ◽  
pp. 748-752 ◽  
Author(s):  
Dmitrii V Sidelev ◽  
Yuriy N. Yurjev
Keyword(s):  
Magnetic Field ◽  
Electrical Discharge ◽  
Strong Dependence ◽  
Field Configuration ◽  
Discharge Voltage ◽  
Deposition Rates ◽  
Discharge Characteristics ◽  
Reactive Deposition ◽  
Uv Visible ◽  
Deposition Mode

The article reports on the aspects of reactive deposition ultra-thin TiOx films (50 nm) by means of dual magnetron system with mirror and closed magnetic field (B field) configurations. The hysteresis effect of electrical discharge characteristics and oxygen partial pressure P(O2) are presented. The dual magnetron with closed B field configuration has less hysteresis peculiarities and transits back to metallic deposition mode at higher O2 flow rate (Q). The deposition rates don’t depend on B field configuration and correlate with changing of P(O2) and discharge voltage. The refractive spectra and energy of band gap, which are measured by UV-visible spectrophotometry and ellipsometry (λ=632.8 nm) methods, have strong dependence on Q(O2).

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