A high-speed digital underwater communication solution using electric current method

The purpose of the work was to determine the capabilities of the pulse effect of electric current and pressure to produce welded joints of various component parts of different thickness from 18-10 stainless steel and titanium. Application of electric current pulses on the surfaces of contacting metallic conductors leads to considerable changes in the surface structure. Depending on the initial state of the surfaces and parameters of the pulse effect this can result in melting without formation of joints, formation of a strong welded joint with characteristics no worse than those of welded metals, and in destruction of the contact zone. A combination of a short electric pulse with simultaneous application of mechanical pressure in the weld zone causes high-speed deformation of the contact zone. The process of joint formation itself does not cause any appreciable diffusion during welding. The greatest energy emission and the maximal heating occur on the contacting surfaces being welded with the passage of an electric current pulse through the welding zone. Simultaneously with intensive heating, and due to applied pressure, high-speed deformation of materials takes place and a strong welded joint is formed. Optimal parameters for the welding of titanium and 18-10 stainless steel have been determined on the basis of the tests conducted. Investigations into the welding of titanium and 18-10 stainless steel have shown that application of a short electric current pulse and pressure produces stronger welded joints composed of both similar and different metals of considerably different thickness.

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Research on the delamination wear properties of the pure carbon strip at the high-sliding speed with electric current

Industrial Lubrication and Tribology ◽

10.1108/ilt-05-2017-0145 ◽

2018 ◽

Vol 70 (1) ◽

pp. 76-83 ◽

Cited By ~ 1

Author(s):

Hongjuan Yang ◽

Lin Fu ◽

Yanhua Liu ◽

Weiji Qian ◽

Bo Hu

Keyword(s):

Electric Current ◽

High Speed ◽

Normal Load ◽

Copper Wire ◽

Electrical Current ◽

Wear Properties ◽

Sliding Speed ◽

Content Type ◽

Delamination Wear ◽

High Speed Data

Purpose This paper aims to investigate the delamination wear properties of a carbon strip in a carbon strip rubbing against a copper wire at the high-sliding speed (380 km/h) with or without electrical current. Design/methodology/approach The friction and wear properties of a carbon strip in a carbon strip rubbing against a copper wire are tested on the high-speed wear tester whose speed can reach up to 400 km/h. The test data have been collected by the high-speed data collector. The worn surfaces of the carbon strip are observed by the scanning electron microscope. Findings It was found that there was a significant increase of the delamination wear with the decrease of the normal load when the electric current is applied. The size of the flake-like peeling also increases with the decrease of normal load. The delamination wear extends gradually from the edge of the erosion pits to the surrounding area with the decrease of the normal load. However, the delamination wear never appears in the absence of electric current. It is proposed that the decreased normal load and the big electrical current are the major causes of the delamination wear of the carbon strip. Originality value The experimental test at high-sliding speed of 380 km/h was performed for the first time, and the major cause of the delamination was discovered in this paper.

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Penentuan Sub-sub Daerah Aliran Stratified Udara-Air pada Pipa Horisontal Menggunakan Constant Electric Current Method (CECM)

Simetris Jurnal Teknik Mesin Elektro dan Ilmu Komputer ◽

10.24176/simet.v4i1.124 ◽

2014 ◽

Vol 4 (1) ◽

pp. 49

Author(s):

Akhmad Zidni Hudaya ◽

Indarto Indarto ◽

Deendarlianto Deendarlianto

Keyword(s):

Electric Current ◽

Current Method

ABSTRAK Visualisasi dan liquid hold-up aliran stratified udara-air pada pipa horizontal sebagai fungsi waktu (dia. dalam pipa 26,0 mm dan total panjang seksi uji 9,5 m) telah diteliti secara eksperimental. Pada penelitian ini, studi visualisasi dilakukan dari analisa data visual yang dihasilkan kamera video kecepatan tinggi dan perilaku tebal film aliran diteliti dengan mengukur liquid hold-up menggunakan Constant Electric Current Method (CECM). Prinsip dari metode ini didasarkan atas perbedaan konduktivitas pada cairan dan gas. Pada penelitian ini digunakan sensor CECM sebanyak 3 buah dengan jarak aksial antar sensor 215 mm. Hasil penelitian ini menunjukkan bahwa karakteristik gelombang antarmuka yang dihasilkan dari pemprosesan sinyal CECM dan studi visual dapat digunakan untuk menentukan sub-sub daerah aliran stratified . Peta pola aliran stratified Udara-Air pada Pipa Horisontal yang dihasilkan dari penelitian ini dipresentasikan dan dibandingkan dengan peta-peta yang ada dari penelitian-penelitian terdahulu. Kata Kunci : Sub-sub daerah aliran, aliran stratified, CECM, gelombang antarmuka

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Wear Properties of Metal-Impregnated Carbon Fiber-Reinforced Carbon Composite Sliding Against a Copper Plate Under an Electric Current

World Tribology Congress III, Volume 1 ◽

10.1115/wtc2005-63457 ◽

2005 ◽

Cited By ~ 1

Author(s):

Shunichi Kubo ◽

Hiroshi Tsuchiya

Keyword(s):

Carbon Fiber ◽

Electric Current ◽

High Speed ◽

Carbon Composite ◽

Copper Plate ◽

Fiber Reinforced ◽

Wear Properties ◽

Copper Disk ◽

Carbon Fiber Reinforced ◽

Arc Discharges

The metal-impregnated carbon fiber-reinforced carbon composite (C/C composite) is expected to be a candidate material for pantograph contact strips of high-speed electric railway vehicles, because its mechanical strength for flexure and impact is much higher than that of the conventional metal-impregnated carbon. The authors have investigated the wear properties of copper-titanium-alloy impregnated C/C composite sliding against a copper disk under an electric current and frequent arc discharges. The tested C/C composite was prepared by press molding and baking of laminated carbon fiber woven sheets. There exists anisotropy in the physical properties originated from the orientation of carbon fiber woven sheets lamination. The C/C composite was slid in two directions, in parallel with or perpendicular to the sheet layer. The test results show that the wear rate in sliding in the parallel direction exceeds that in the perpendicular direction, especially in the cases where the material is subjected to higher current density and more frequent arc discharges.

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