Arc erosion property and mechanism of tungsten–copper alloy with multi-scale tungsten particles

In this work, tungsten–copper (W–Cu) alloy with multi-scale tungsten phase was prepared by cold isostatic pressing, vacuum sintering and hot extrusion processes. The microstructure of W-70Cu alloy was examined by scanning electron microscopy and transmission electron microscopy. The arc erosion resistance of W-70Cu alloy was studied in the JF04C electrical contact testing system. The erosion morphology of the contact surface was characterized. The action mechanism of tungsten particles in arc erosion process was discussed in detail. The arc erosion property and mechanism of W-70Cu alloy were analyzed. The results show that the material transfer occurs from the cathode to the anode. With enhancing the current and voltage, the arcing time and arcing energy increase while the contact resistance falls slightly. In the arc erosion process, tungsten particles increase the work function of W–Cu alloy and make the arc disperse better. The large tungsten particles in W–Cu contact can help to maintain the shape of the contact and delay the occurrence of fusion welding. Tungsten nano-particles enhance the viscosity of the molten pool, reduce metal splashing, and hinder the crack initiation and propagation. Under the action of multi-scale tungsten particles, W–Cu alloy has the better resistance to arc erosion.