In situ formation and doping of Ag/SnO₂ electrical contact materials

The Ag/SnO₂ electrical contact materials with different doping concentration of Zr and Fe were successfully fabricated through self-assembly precipitation and powder metallurgy method. The microstructures of Ag-SnO₂ composite powders and the prepared Ag/SnO₂ contact materials were investigated by a Scanning Electron Microscopy (SEM) coupled with EDS and EBSD systems. The results showed that the SnO₂ nanoparticles with typical geometric shapes were formed and distributed in Ag matrix. The electrical conductivity of the Ag/SnO₂ materials was significantly increased by 16 percent with the doping of 3 wt% ZrO₂ in SnO₂. The surface morphology of the Ag/SnO₂ materials after arc erosion was further characterized. The formation of the Sn(Zr)O₂ and Sn(Fe)O₂ solid solution in Ag/SnO₂ significantly improved the arc dispersion and arc erosion resistance. This work can offer a novel approach to design Ag/SnO₂ contact materials for good electrical performances. - Highlights: • The Zr and Fe doped Ag/SnO₂ electrical contact materials were prepared. • The electrical conductivity was significantly increased with the doping of ZrO₂ in SnO₂. • The formation of SnO₂(ZrO₂) solid solution significantly improved the arc erosion.