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Enhancing mechanisms of arc-erosion resistance for copper tungsten electrical contact using reduced graphene oxides in situ modified by copper nanoparticles.
- Source :
-
International Journal of Refractory Metals & Hard Materials . Nov2022, Vol. 108, pN.PAG-N.PAG. 1p. - Publication Year :
- 2022
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Abstract
- To solve critical issues of premature failure for copper tungsten (CuW) based electrical contacts during arc erosion at the moment of arc breakdown, we proposed a new strategy of using metal doped reduced graphene oxides (rGOs) and in-situ formed tungsten carbides to inhibit movements of cathode spots during the arc ablation process. CuW composites were reinforced with Cu modified rGO nanopowders (i.e. Cu@rGO) using combined processes of chemical co-reduction, ball milling and spark plasms sintering (SPS). Effects of Cu@rGO addition on microstructure, arc erosion resistance and arc ablation resistance of the CuW composites were systematically investigated. Results showed that tungsten carbides with irregular shapes were formed through in-situ reactions of rGO and tungsten during the SPS process. Arc erosion resistance of CuW composites was significantly improved owing to introduction of nanostructured Cu@rGO. Compared with those of CuW composites, the ablation areas of Cu@rGO/CuW ones were much smaller and the ablation craters were shallower, and the average strengths of dielectric vacuum breakdowns of the CuW composites with 3 wt% Cu@rGO were increased by 28.9%. The arc breakdown mechanisms of Cu@rGO/CuW composites were identified as: (1) The nanostructured Cu@rGO increases the viscosity of molten metal Cu, thus inhibiting its fast flow and splashing; (2) Lower work functions of carbon (i.e. rGO) and tungsten carbide restrain the electron emissions during arc breakdown; and (3) The tungsten carbides with their good stability and high melting point shorten the solidification time of molten copper liquid and extend the service life time of the Cu@rGO/CuW composites. • Introduced nanostructured Cu@rGO into CuW improve effectively dispersion effect. • Cu@rGO/CuW composites with smaller ablation area and shallower ablation craters. • Average arc breakdown strength of 3wt%Cu@rGO/CuW composites increased by 28.9%. • Arc breakdown mechanism were attributed to increasing of the viscosity of molten Cu, lower work functions of second phases. • Provides a new thought of enhanced arc erosion resistance of CuW with graphene decorated with metal nanoparticles. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 02634368
- Volume :
- 108
- Database :
- Academic Search Index
- Journal :
- International Journal of Refractory Metals & Hard Materials
- Publication Type :
- Academic Journal
- Accession number :
- 158608750
- Full Text :
- https://doi.org/10.1016/j.ijrmhm.2022.105934