Enhanced arc erosion resistance of TiB2/Cu composites reinforced with the carbon nanotube network structure

The continuous network structure induced by carbon nanotubes (CNTs) was introduced to TiB2/Cu composites by electroless deposition, slurry dispersion and powder metallurgy to enhance arc erosion resistance. The arc erosion characteristics of the TiB2/Cu-CNT composites at a current ranging from 10 A to 20 A were investigated. The mechanisms of enhanced arc erosion resistance by the CNT network structure were elaborated based on microstructure and physical characteristics as well. The results show that with the introduction of continuous CNT network structure, arc energy was reduced by more than 83%, there were almost no fluctuation of arc energy and the welding force was relatively low at current above 15 A for TiB2/Cu-1.2 vol% CNT composite in comparison with the CNT unreinforced TiB2/Cu composite. The continuous network structure facilitated the cathode arc motion and dispersed the cathode arc, mitigating the concentrated deterioration of arc erosion. Simultaneously, CNTs could float much easily at the surface of molten pool to weaken the Cu splashing. The CNT network structure delayed the formation of the deeper crater on the cathode and the protrusion with a sharper tip on the anode. Furthermore, it could prevent the formation of cracks and fracture of anode protrusion.