Experiment investigation on vacuum arc of AMF contacts under different materials

In this paper, the arc characteristics of cup-shaped AMF contacts in vacuum arc experiments under different materials was studied. The experiment was conducted in a detachable vacuum chamber with a gas pressure of 10-4Pa. The arc voltage and current were measured at the same time by high-voltage probe and Rogowski coil, and the arc pictures were photographed with a high-speed camera. The cup and the rod of the contact are made of pure copper material, and the contact pieces are selected ten common contact materials for comparison (CuCr10, CuCr 20, CuCr 30, CuCr 40, CuCr 50, WCu10, WCu20, WCu30, CuW-WC). Fixed-distance trigger experiments were conducted with currents of 5kA (rms), 10kA (rms), and 15kA (rms) for each contact. The arc appearance, cathode surface morphology, and anode status morphology were observed. The shape of the arc was analyzed in conjunction with the voltage and current after the experiment. The morphology of cathode and anode surface was analyzed by combining the erosion after the experiment. The effect of various material properties was discussed under the AMF. It’s found that the center of the anode erosion area is approximately hexagonal, and the slot is burned more outward than the plane. WCu contact has better erosion resistance than CuCr contact. For CuCr, the erosion of CuCr30 is the slightest with low depth and small area.