Effect of La_(2)Sn_(2)O_(7)content on Ag-La_(2)Sn_(2)O_(7)/SnO_(2)arc erosion behavior and mechanism

La_(2)Sn_(2)O_(7)/SnO_(2)powder was synthesized by chemical co-precipitation method,and Ag-La_(2)Sn_(2)O_(7)/SnO_(2)composites were prepared by hot-pressing sintering.The electrical resistivity,density,Brinell hardness and flexural strength of Ag-La_(2)Sn_(2)O_(7)/SnO_(2)composites were measured.Moreover,the effect of La_(2)Sn_(2)O_(7)content on the arc erosion behavior of Ag-La_(2)Sn_(2)O_(7)/SnO_(2)composites at 7 kV voltage was studied.With the increase of La_(2)Sn_(2)O_(7)content,the arc duration and arc energy decrease,and the breakdown strength increases.The surface morphology of Ag-La_(2)Sn_(2)O_(2)/SnO_(2)composites after arc erosion was investigated using scanning electron microscopy and three-dimensio nal laser confocal scanning microscopy.With the increase of La_(2)Sn_(2)O_(7)content,the smaller the erosion damage,the better the anti-arc erosion performance.However,too much La_(2)Sn_(2)O_(7)results in the decrease of Ag-La_(2)Sn_(2)O_(7)/SnO_(2)properties and severe arc erosion.X-ray photoelectron spectroscopy was used to determine the composition of the erosion region.The effect of La_(2)Sn_(2)O_(7)on wettability between Ag and SnO_(2)was investigated,and the erosion mechanism of Ag-La_(2)Sn_(2)O_(7)/SnO_(2)composites was discussed systematically.This study can provide a reference for the application of Ag matrix electrical contact materials in high-voltage electrical appliances.