Study on preparation and arc behavior of CuCr40 contact materials for Bi doped switch cabinet

This study combines high-energy ball milling with spark plasma sintering (SPS) technology to prepare CuCr40 electrical contact materials with different Bi doping contents. The hardness, electrical conductivity, density, and the behavior of surface arc motion and erosion morphology during the electrical breakdown process of the contacts were characterized, and their arc erosion resistance was analyzed. The results show that CuCr alloys doped with 2.5% and 7.5% Bi can meet the basic performance requirements of contact materials. After vacuum cathode discharge, the contact with 7.5% Bi doping has a larger cathode spot area and a shallower peripheral ablation zone, demonstrating good arc dispersion characteristics. At the same time, after arc ablation, the Bi-doped contacts show no significant ablation pits or cracks. The comprehensive research results indicate that the CuCr contact with 7.5% Bi doping exhibits good arc motion and arc erosion resistance characteristics.