Fracture Behavior of Droppers under Low Current Pulses and Stress Coupling Cyclic Fields

Abstract In traction power supply catenary systems of high-speed railways, integral droppers convey current for the use of the electric locomotive. Based on real electro-mechanical coupling conditions of high-speed rail catenary droppers, the microstructure and fracture morphology formation and changes of the copper-magnesium alloy wire (Cu-Mg0.4) resulting from the effect of current pulses of low density (10 A/$ mm^{2} $), short durability (0.25 s), and interval (5 min) were studied in this work, accompanied by low dynamic stress (30 MPa) and compression strain (0.3%) under long-term working cycles. The simulation and test results indicated the temperature increase in the droppers in the working state was slightly higher than room temperature. In these experiments, a large number of micropores were generated in the pre-rolled alloy wire droppers. Under the long-term action of low stress and amplitude pulse coupling fields, the droppers retained the fiber structure characteristics without obvious recrystallization; however, similar shear band structures appeared in the fiber structures, which were bent and deformed, and the micropore density increased. The micropores aggregated into microcracks and expanded, resulting in a gradual decrease in plasticity, and the fracture mode transformed from ductile trans-granular fractures to brittle inter-granular fractures, corresponding to deeper and shallower dimples, respectively..

Medienart:

E-Artikel

Erscheinungsjahr:

2022

Erschienen:

2022

Enthalten in:

Zur Gesamtaufnahme - volume:32

Enthalten in:

Journal of materials engineering and performance - 32(2022), 18 vom: 13. Dez., Seite 8346-8357

Sprache:

Englisch

Beteiligte Personen:

Wu, Wenjiang [VerfasserIn]
Wang, Zhengri [VerfasserIn]
Fu, Hua [VerfasserIn]
Zheng, Mingjun [VerfasserIn]
Gao, Zhanfeng [VerfasserIn]

Links:

Volltext [lizenzpflichtig]

Themen:

Dropper
Electron-mechanical coupling
Electroplastic effect
Fracture behavior

Anmerkungen:

© ASM International 2022. Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.

doi:

10.1007/s11665-022-07697-1

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

OLC2145468684

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