Tribological behaviour of graphite/graphite and graphite/copper couples in sliding electrical contact: influence on the contact electric field on the surface passivation

Purpose This paper aims to study the effect of load on the tribological behaviour of Cu-based composites, so as to obtain a suitable applied load on these composites. Design/methodology/approach Cu-based composites were prepared by powder sintering with direct current electric current heating and tested by Universal Mechanical Test-3 with a ball-on-disk at room temperature. Findings The results showed that Cu-based composites are might suitable for working under low load. There is only mild damage on the surface under a load of 2 N. While it has microcracks and shows signs of cavitation at a certain depth at 20 N and 50 N. In addition, it is evident that there are three zones in the cross-section of the matrix, namely, a mechanical mixing layer, ceramic layer and substrate, respectively. Originality/value There are two wear mechanisms at different loads, and the evolution of worn surfaces with sliding time is also involved. Thus, the developed material can be used for light load sliding electrical contact material applications.

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Interaction of tungsten in dry sliding against steel under high density electric current

Voprosy Materialovedeniya ◽

10.22349/1994-6716-2019-97-1-101-109 ◽

2019 ◽

pp. 101-109 ◽

Cited By ~ 2

Author(s):

M. I. Aleutdinova ◽

V. V. Fadin ◽

Yu. P. Mironov

Keyword(s):

Electrical Contact ◽

Analysis Data ◽

Dry Sliding ◽

Sliding Surface ◽

X Ray ◽

Sliding Surfaces ◽

Quenched Steel ◽

Sliding Electrical Contact ◽

A Current ◽

Tungsten Steel

The possibility of creating a wear-resistant dry sliding electrical contact tungsten/steel was studied. It was shown that tungsten caused severe wear of the quenched steel counterbody due to unlimited plastic flow of its surface layer at a current density up to 150 A/cm2 . This indicated the impossibility of achieving satisfactory characteristics of such a contact. Low electrical conductivity and wear resistance of the contact tungsten/steel were presented in comparison with the known high copper/steel contact characteristics under the same conditions. X-ray phase analysis data of the steel sliding surfaces made it possible to state that the cause of the unsatisfactory sliding of tungsten was the absence of the necessary concentration of FeO oxide on the sliding surface of the steel.

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Analysis of Rail-Armature Linear Resistance Density as the Characterization Parameter for the Sliding Electrical Contact Performance of the Railgun

IEEE Transactions on Plasma Science ◽

10.1109/tps.2019.2948035 ◽

2019 ◽

Vol 47 (11) ◽

pp. 5006-5012

Author(s):

Shizhong Li ◽

Ronggang Cao ◽

Tao Li ◽

Jun Li

Keyword(s):

Electrical Contact ◽

Linear Resistance ◽

Sliding Electrical Contact

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The Fabrication of Mercuric Iodide Detectors for Use in Wavelength Dispersive X-Ray Analysers and Backscatter Photon Measurements

MRS Proceedings ◽

10.1557/proc-16-207 ◽

1982 ◽

Vol 16 ◽

Cited By ~ 10

Author(s):

John H. Howes ◽

John Watling

Keyword(s):

Room Temperature ◽

Gamma Ray ◽

Surface Passivation ◽

Electrical Contact ◽

Scintillation Counter ◽

Radiation Detectors ◽

Nuclear Radiation ◽

Gamma Ray Spectrometry ◽

Mercuric Iodide ◽

X Ray

ABSTRACTThis paper describes the fabrication of mercuric iodide nuclear radiation detectors suitable for X and gamma ray spectrometry at room temperature. The active area of the detectors studied are between 0.2 and 1.5cm sq and they are up to 0.5mm thick. The method of producing a stable electrical contact to the crystal using sputtered germanium has been studied. The X-ray resolution of a 1.5cm sq. area detector at 32 keV is 2.3 keV FWHM when operated at room temperature in conjunction with a time variant filter amplifier. A factor which is important in the fabrication of the detector is the surface passivation necessary to achieve a useful detector life.This type of detector has been used on a wavelength dispersive X-ray spectrometer for energy measurements between 10 and 100 keV. The advantages over the scintillation counter, more commonly used, is the improved resolution of the HgI2 detector and its smaller size. The analyser is primarily used for the detection of low levels of heavy metals on particulate filters. The detectors have also been used on an experimental basis for gamma ray backscatter measurements in the medical field.

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