Arc erosion behaviour of in-situ TiB2/Cu composites with a three-dimensional network structure

Copper matrix composites (CMCs) with tailored heterogeneous structures at the mesoscopic scale are promising candidates for electrical contact materials. In this work, CMCs reinforced by an in situ formed three-dimensional network of TiB 2 particles were synthesized from Cu, Ti and B powder mixtures by reactive hot-pressing. The arc erosion behaviour of the fabricated CMCs was investigated by an electrical contact test. The distribution state of in situ TiB 2 depends on the particle size of the Cu powder. The critical size for forming a continuous network in 3 wt%TiB 2 /Cu composites is estimated to be 24 μ m. Once the continuous network is formed in CMCs, the arc energy and duration suddenly change to ultrasmall and stable values, and the erosion area and total mass loss after 5000 cycles of the contact test remarkably decrease. The results indicate that the CMCs reinforced by in situ networks of TiB 2 particles exhibit excellent arc erosion resistance.