Experimental investigation of high-current vacuum arc anode phenomena in WCu alloy contacts

Compared with CuCr electrodes, WCu electrodes have better resistance to welding, making them a research hotspot in vacuum switch fields. This work investigates the vacuum arc characteristics of WCu butt contacts. The contacts, with a diameter of 15 mm, are made of WCu10, WCu30, and WCu-WC. The opening speed is 1.7 m/s, and the experimental current ranges from 2.5 to 7.7 kA. The results indicate that anode spot type 2 and anode plumes occur not only on CuCr contacts but also on WCu contacts, which updates the previous findings. WCu contacts produce more cathode droplets than CuCr contacts, and residual droplets remain after current zero. Increasing Cu content in WCu contacts shortens the formation time of anode spot type 2 and reduces inter-electrode metal droplets. WC can reduce droplet formation and enhance the erosion resistance of WCu contacts. Additionally, the current exerts a stronger influence on the transferred charge before anode spot type 2 in WCu contacts compared to CuCr contacts.