The Influence of the Microstructure on the Switching Properties of Ag C, Ag-WC-C and Ag-W-C Contact Materials

Abstract

The correlation between the microstructure of Ag-C, Ag-WC-C and AgWC composites and their switching properties was investigated. Two methods were used to manufacture the starting powder mixtures, namely classical milling and mechanical alloying . The arc erosion, contact resistance and welding forces of the contact materials obtained by different methods were measured using model devices. This paper presents the results achieved for the tested materials. It was found that weight loss was lower for the contacts produced by high energy milling.Keywords: electrical contacts, microstructure, switching properties, mechanical alloying W pracy badano wpływ mikrostruktury kompozytów Ag-C oraz Ag-WC-C i Ag-W-C na ich właściwości łączeniowe. Do wytworzenia kompozytów stosowano dwa sposoby przygotowania mieszanin wyjściowych: klasyczne mieszanie proszków oraz mechaniczną syntezę (MA -mechanical alloying). Porównano odporność kompozytowych materiałów stykowych wykonanych różnymi technologiami na erozję łukową, rezystancje zestykową i odporność na sczepianie. Badania właściwości łączeniowych prowadzono w układach modelowych. Stwierdzono, że zastosowanie procesu MA do przygotowania mieszanin wyjściowych powoduje wzrost odporności na erozję badanych materiałów.

Effects of Different Post-Treatments on Arc Erosion Resistance of Cold-Sprayed AgC Composite Electric Contact

“…When the erosion cycle increased to 10,000, mass pores appeared To reveal the specific erosion behaviors of the coatings clearly, magnified images of the erosion area for the as-deposited AgC, annealed AgC and laser-scanned AgC samples after 10,000 switching operations are presented in Figure 7ai-ci. As shown in Figure 7ai for the as-deposited AgC coating, common morphologies caused by arc erosion such as island-like melted silver, evident spherical silver, some pores and small cracks can be clearly observed [23,24]. The annealed sample exhibited a similar erosion morphology with the as-deposited sample.…”

Influence of Heat Treatment Condition on the Microstructure, Microhardness and Corrosion Resistance of Ag-Sn-In-Ni-Te Alloy Wire

“…Ag-based electrical contact materials such as AgMeO [ 1 ], AgNi [ 2 ], AgC [ 3 ], AgWC [ 4 ] and AgZrB 2 [ 5 ] are presently among the most widely employed options in the field. Various AgMeO electrical contact materials, including AgCdO [ 6 ], AgSnO 2 [ 7 ], AgZnO [ 8 ], AgZnO 2 [ 9 ], AgCuO [ 10 ], AgY 2 O 3 [ 11 ] and Ag(MgCoNiCuZn)O [ 12 ] have been developed due to their exceptional electrical contact properties, improved resistance to welding and arc erosion, as well as enhanced thermal and electrical conductivity.…”

Infiltration Behavior Of Mechanical Alloyed 75 wt% Cu-25 wt% WC Powders Into Porous WC Compacts

“…On the other hand they have poor electrical and thermal conductivities and they do not show resistance against oxidation. In order to compensate these drawbacks usually transition metals are added to refractory metals and their carbides leading a composite matrix [4][5][6]. Electrical contacts are one of the well-known application fields of these composites and it is expected to withstand high currents and more arcing than other usual contact materials [6][7][8][9][10][11].…”