Anti-Arc Erosion Properties of Ag-La2Sn2O7/SnO2 Contacts

La2Sn2O7/SnO2 composite powder was synthesized by chemical co-precipitation, and Ag-La2Sn2O7/SnO2 electrical contact material was prepared by a powder metallurgy method. Anti-arc erosion properties, mass loss and Vickers hardness of the Ag-La2Sn2O7/SnO2 composite were investigated, and its anti-arc erosion mechanism was discussed. Results show that the welding force of Ag-La2Sn2O7/SnO2 composite is much better than that of Ag-SnO2, because the new phase La2Sn2O7 can increase the viscosity of melt pool and improve wettability between silver and tin oxide to some extent. Meanwhile, Flatter arcing area and “beads-like” particles embedded scatteredly in the surface could decentralize arc energy via “pinning effect”, which decreases temperature rise and weakens the damage of surface structure, and better anti-welding property is obtained. Ag-La2Sn2O7/SnO2 composite could be a leading candidate material for electrical contacts in the future.