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6516 |
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Arc erosion resistant coatings deposited via cold gas spraying |
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Mario Tului* / Centro Sviluppo Materiali S.p.A., Italy Xavier Hallet / LaserCo DT, Belgium Guido Scarcello/ CSM SpA, Italy Angelo Luigi Marino/ CSM SpA, Italy Norberto Jimenez/ CRM Group, Belgium |
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Preliminary results obtained in the frame of a European project called INCOMARC will be presented. The project aims to develop new coating materials for Electrical Contacts (EC); in particular connectors for non-stationary applications and high and medium power applications, which are subject to a wide variety of stress such as erosion due to electric arcs, leading to decreased performances and a shortened components lifespan. Currently, the material mainly used in EC production for high and medium power is the Ag with Cadmium oxide as hard ceramic phases. These two materials present two limitations: CdO is restricted by the European Commission because of Cadmium toxicity, while Silver use is not recommended: resources are very poor and with the actual consumption rate, 17.000 tons per year (data from 2014), silver will be exhausted in a few decades. Candidate coating materials were designed after an analysis of the state of art. They are hard particles (e.g., W, WC, Sn02) embedded in a Cu metal matrix, where hard phases are stable materials, even in temperature, with high hardness and high electrical conductivity. The use of sub-micron ceramic particles will be investigated, in order to increase the effect on hardness and on powder distribution, that is fundamental for arc extinction ability. Preliminary deposition campaigns were performed to assess the influence of deposition parameters on conductivity, hardness, adhesion, corrosion resistance, etc. Further deposition campaigns will be conducted to optimize the properties of the coating |