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 TiB2 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 TiB2 depends on the particle size of the Cu powder. The critical size for forming a continuous network in 3wt.%TiB2/Cu composites is estimated to be 24 μm. 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 TiB2 particles exhibit excellent arc erosion resistance.

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