Effect of Fe on microstructures and vacuum arc characteristics of CuCr alloys

In order to clarify the effect of Fe addition on vacuum arc characteristics of CuCr alloys, the CuCr50, CuCr45Fe5 and CuCr40Fe10 alloys were prepared by vacuum sintering and infiltrating, and the simulated electrical breakdown experiment was undertaken in a vacuum interrupter. The characteristics of the motion of vacuum arcs were analyzed by a digital high-speed video camera and the erosion morphology was characterized by a scanning electron microscope (SEM). The results show that Fe additions can strengthen the Cr phase, promote the first breakdown phase to transfer from Cr to Cu and increase the strength of the alloy breakdown voltage by 80%. Meanwhile, Fe additions can still retain the arc stability of CuCr50 alloys during the generation and extinguishing process, decrease the chopping current, and prolong the arc life. Furthermore, the characteristics of the split and motion of cathode spots on the surface of the CuCr40Fe10 alloy were improved, which prohibits the concentrated arc erosion.