Influence of WC particles addition on material transfer behavior of CuCr30 contact material

CuCr30 contact materials were commonly applied in medium voltage vacuum interrupters. To further improve the welding resistance of CuCr30, micron-sized WC particles were introduced into the CuCr30 contact material by vacuum hot-pressing sintering. Electrical contact tests were conducted on the JF04C electrical contact material testing system and the experimental parameters were voltage 24 V DC, current 14 A, 20 A, and 26 A. Comprehensive experimental results show that the micro-Cr particles were uniformly distributed in the Cu matrix and the relative density of WC/CuCr30 contact materials as high as 99% has been obtained. In the arc erosion process, WC particle addition benefits to increase the molten pool area and inhibit the continuous deepening of the molten pool. WC/CuCr30 contact material is dominated by cathodic corrosion. The mass is transferred from the cathode to the anode at different currents. WC particles increase the viscosity of the molten pool of CuCr30, which is beneficial to reduce the welding force and improve the welding resistance of WC/CuCr30 contact material. However, WC particles reduce the thermal conductivity of WC/CuCr30 contact material, leading to a higher mass loss due to heat accumulation on the contact surface.