Synergistic effects of graphene and nano-W dispersion on mechanical, electrical and arc erosion behaviors of Cu-10W composites

Electrode materials typically suffer from an inherent trade-off between arc erosion resistance and electrical conductivity. In this work, Cu-10W composites containing of 0, 0.1, 0.3, and 0.5 wt% graphene (Gr) was fabricated via near-net-shape hot isostatic pressing (HIP), and their microstructures and properties were systematically investigated. Among these composites, the Cu-10W-0.1Gr composite exhibited the most balanced performance, achieving a relative density of 98.57%, tensile strength of 317 MPa, elongation of 22.2%, and electrical conductivity of 87.6%IACS. Microstructural analysis revealed that the mechanical and electrical enhancements mainly originated from the dispersion strengthening induced by nano-sized W particles dispersed within the Cu matrix, combined with the optimization of the conductive network by Gr located at grain boundaries. Benefiting from the high electrical conductivity and low work function of Gr, under a 30 V DC and 35 A test condition, the addition of a 0.5wt.%Gr reduced mass loss and erosion rate by up to 24.0%, decreased average arc energy by up to 47.9%, effectively suppressed welding force, and maintained stable contact resistance. This work mitigates the longstanding strength-conductivity dilemma in Cu-based electrode materials, and provides a viable design strategy for high-performance electrical contact composites.