scholarly journals Vacuum Arc Ion Flux From Vacuum Interrupter Contact Gap

2017 ◽  
Vol 4 (2) ◽  
pp. 186-189
Author(s):  
M. Kurrat
Keyword(s):  
Layer Thickness ◽  
Metal Layer ◽  
Transport Processes ◽  
Ion Flux ◽  
Vacuum Arc ◽  
Ceramic Surface ◽  
Metal Vapour ◽  
Particle Tracing ◽  
Final Particle ◽  
Dielectric Performance

Dielectric properties of vacuum interrupters are influenced by metal vapour deposition on the inner ceramic surfaces. Therefore these surfaces are partly protected by shield electrodes. The metal vapour originates from the vacuum arc in the contact gap during switching off process. Metal layer thickness on ceramics after switching operations were measured by Gramberg and the negative effect on dielectric performance was demonstrated. In this paper we address the principle transport process of metal vapour in vacuum interrupters. Duning and Beilis performed ion flux measurements from vacuum arcs. We regard experiments with 5 kA effective arc current. There seems to be experimental evidence that the final particle transport onto the ceramic surface within a shield gap can be explained by particle tracing. The measured deposited layer thickness is taken as quantity to validate vapour densities and transport processes in vacuum interrupters.

Ion flux from the cathode region of a vacuum arc

1989 ◽  
Vol 17 (5) ◽  
pp. 688-694 ◽  
Author(s):  
J. Kutzner ◽  
H.C. Miller
Keyword(s):  
Cathode Region ◽  
Ion Flux ◽  
Vacuum Arc

Micro Characteristic of Metal Vapour Vacuum Arc

2020 ◽  
Author(s):  
Hai Chen ◽  
Xiaoming Liu ◽  
Peiyuan Li ◽  
Xusong Zhang ◽  
Yaqian Zhang ◽  
...  
Keyword(s):  
Vacuum Arc ◽  
Metal Vapour

DEVICE REALIZATION OF MAGNETIC METHOD FOR DEFINITION OF METAL STRENGTHENED LAYER THICKNESS IN ROLLING-STOCK AXLE

2021 ◽  
Vol 2021 (2) ◽  
pp. 28-37
Author(s):  
Yuriy Livcov ◽  
Vladimir Bezkorovaynyy ◽  
Andrey Kireev
Keyword(s):  
Magnetic Properties ◽  
Layer Thickness ◽  
Metal Layer ◽  
Rolling Stock ◽  
Magnetic Method ◽  
Cold Plastic Deformation ◽  
Natural Experiments ◽  
Micro Hardness ◽  
Scattering Field ◽  
Definition Of

The simplest and accessible method for rolling-stock axle surface strengthening is surface processing with cold plastic deformation by means of rolling. This process is one of the stages in manufacturing diesel locomotive and car axles of a rolling-stock. The basic parameters of rolling engineering process are micro-hardness of a metal surface strengthened layer and its depth, which at present are controlled by means of cutting out longitudinal polished specimens from the axle and in case of the deviation from the required value the whole set axles is rejected. That is why there is offered a method of the non-destruction control of micro-hardness and depth of axle strengthening the essence of which is not only in the control of a strengthening degree value, but in the instant correction of rolling equipment in case of the deviation from the parameter, as this device is integrated in the interface of a rolling machine. In such a way, an actual value of strengthened layer micro-hardness will be always within the specified limits. The principle of device operation is based on the topography changes in the scattering magnetic field of preliminary magnetized local volume of ferromagnetic material. There are shown numerical experiments for the dependence parameter definition of a scattering field of a magnetic mark from thickness and magnetic properties of a strengthened metal layer which had given a possibility to obtain the analytical dependences of a strengthened layer thickness and coercive force of the strengthened layer upon the parameters of a horizontal and vertical constituents of the scattering field strength of the magnetic mark. There are obtained results of natural experiments which allow defining magnetic properties of the upper metal layer in the axle and checking the correctness of data obtained at numerical computations, computation errors do not exceed 6%. The integration circuit of the mentioned structure-scope in the configuration of a rolling machine to obtain a feedback on a micro-hardness value of a surface strengthened layer.

Unified Analysis of the Metal Vapour Arc

1973 ◽  
Vol 28 (3-4) ◽  
pp. 417-428 ◽  
Author(s):  
G. Ecker
Keyword(s):  
Space Charge ◽  
Electron Temperature ◽  
Current Density ◽  
Space Charge Region ◽  
Decisive Role ◽  
Emission Current Density ◽  
Mean Free Path ◽  
Vacuum Arc ◽  
Metal Vapour ◽  
Cathode Drop

Abstractfor given values of the total current density j and the cathode spot surface temperature T a unified and consistent calculation of the cathode drop, Uc , the electron temperature in the ionization region T _- the electron emission current density je , the ion current density j+ , and the extension of the space charge region lsp are presented.We find that the counter diffusion of plasma electrons into the space charge region plays a decisive role. It causes an effective space charge region extension lsp of a few plasma electron Debey lengths which in general is much less than the ion mean-free-path commonly used. Without the effect of the counter diffusing electrons, the theoretical results deviate from the experimental data by orders of magnitude.For the example of a Cu metal vapour-or vacuum arc the cathode drop is found to be approximately Uc = 15 [V], the electron temperature about T- =25000 [°K] and the ratio j+/j= 0.5.Since the analysis allows for multiple ionization the presence of multiply charged ions in the spot area can be calculated.The results of this investigation justify within the E-areas the approximations used in the analysis for the copper arc in an earlier investigation 1. Outside these E-areas a recalculation with the new results derived here may cause markable changes.

scholarly journals Impact of the Metal Evaporation Rate in Vacuum Interrupters on Vapor Expansion and Deposition in Vacuum

2019 ◽  
Vol 6 (2) ◽  
pp. 165-169
Author(s):  
A. E. Geisler ◽  
N. Wenzel
Keyword(s):  
Ceramic Surface ◽  
High Current ◽  
Extended Version ◽  
Metal Vapour ◽  
Current Case ◽  
Vacuum Interrupter ◽  
Ceramic Surfaces ◽  
Metal Evaporation ◽  
History Of ◽  
Interaction History

The emission of contact material into vacuum after switching operation of a vacuum interrupter is crucial for the metallisation of the ceramic surfaces. This work focuses on the simulation of various regimes of metal vapour pressure using an extended version of an existing DSMC code that now allows the visualisation of the interaction types and locations during the vapour expansion. The model was applied to a typical vacuum interrupter geometry at different current levels between 3 A and 100 kA. The simulations show that in the low current case the likelihood for a particle hitting a ceramic surface can be more than a factor of 5 higher than in the high current case. An explanation of this observation will be given by analysing the interaction history of the respective particles.

scholarly journals Growth and Mechanical and Tribological Characterization of Multi-Layer Hard Carbon Films

1996 ◽  
Vol 438 ◽  
Author(s):  
J. Ager ◽  
I. Brown ◽  
O. Monteiro ◽  
J. A. Knapp ◽  
D. M. Follstaedt ◽  
...  
Keyword(s):  
Layer Thickness ◽  
Carbon Films ◽  
Vacuum Arc ◽  
Individual Layer ◽  
Implantation Damage ◽  
Film Hardness ◽  
Sublayer Thickness ◽  
Pin On Disk ◽  
Tribological Characterization ◽  
20 Nm

AbstractVacuum-arc deposition is used to deposit multilayer carbon films by modulating the sample bias during deposition. The effect of varying the sublayer thickness in multilayer films consisting of alternating layers of “hard” (68.4 GPa, -100 V bias) and “soft” (27.5 GPa, -2000 V bias) was investigated. Films consisting of equal thickness layers of hard and soft material and an individual layer thickness varying from 10 to 35 nm were deposited. Mechanical property measurements were obtained by finite element modeling of nanoindentation load-displacement curves. The film hardness values were about 20% below the average of the component layers and relatively independent of the layer thickness. TEM investigation revealed deterioration of the multilayer structure when the sublayer thickness was below 15 nm due to implantation damage of the hard layers caused by the energetic C+ ions of the soft layers (-2000 V bias) deposited over them. Pin-on-disk wear tests show that the wear rate drops when sublayer thickness is decreased below 20 nm and remains constant with further decreases in the layer thickness.

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