In order to improve the comprehensive properties of Ag-SnO2 electrical contact materials,highly efficient densification of the materials was successfully realized by a simple and feasible vacuum hot repressing. The effects of the addition of nano and sub-micron NiO on mechanical and arc erosion resistance properties were further investigated,and the correlative mechanism was explored. The microstructure and arc erosion morphology of the materials prepared in this way were characterized by using electron backscatter diffraction (EBSD) and scanning electron microscopy (SEM). The results showed that the relative density of Ag-SnO2 materials with nano NiO significantly increased,reaching up to 99.78％,and the conductivity exceeded 72％IACS. Nano NiO increased the compressive strength of the Ag-SnO2 materials,while the submicron NiO led to a downward trend of the ultimate strain. The arc erosion resistance of the Ag-SnO2 materials can be significantly enhanced by NiO. The high-temperature evaporation and pore formation on the electrode surface were inhibited. Due to a decrease in arc energy and viscosity of melt pool,the mass loss of the materials was significantly reduced. Compared with pure Ag-SnO2,Ag-SnO2 doped with sub-micron NiO had the finer grains and the lowest mass loss,with a decrease of 36.5％ for the anode and 43.8％ for the cathode,respectively.
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