Abstract:A series of Cu Modified AgSnO2In2O3 electrical contact materials were prepared by alloy melting—internal oxidation method. The temperature rise and electrical life testing system were used to evaluate the performance of Cu Modified samples. The 3D microstructure, phase composition, micro morphology and chemical composition of Cu Modified samples were characterized by ex-situ VR 3D projection technology, XRD and SEM/EDS, and the failure mechanism of electrical life endurance was explored. The results show that with the increase of Cu doping content, the microstructure of the modified samples changes from short whisker like oxide to slender fibrous like oxide. However, when the Cu doping content is as high as 6.8 wt.%, the phenomenon of "dissolution-segregation" occurs, a large number of oxide particles preferentially segregate at the grain boundary. The temperature rise behavior of the modified AgSnO2In2O3 contact material decreases first and then increases with the increase of Cu doping. When the copper doping is 2.15 wt.%, the average temperature rise is as low as 76.558k. The order of electrical life service capability of series Cu Modified AgSnO2In2O3 materials is as follows: Cu (2.15) > Cu (1.65) > Cu (1.1) > Cu (3.4) > Cu (4.0) > Cu (6.8). The corresponding electrical life failure mode is fusion welding, which is mainly due to the failure characteristics such as microcracks, enrichment of high proportion (Ag, Cu) microstructure or (Sn, Cu) microstructure and large-area splashing in the process of arc erosion.