In-situ synthesis nitrogen-doped graphene/Cu composites with enhanced mechanical and electrical properties

For graphene/metal composites, both the synthesis of graphene and the interfacial bonding with the metal matrix are crucial for determining overall performance. In this study, in-situ nitrogen-doped graphene/Cu composites were successfully fabricated using polyacrylonitrile (PAN) as the carbon source, and the effects of PAN-derived graphene on composite microstructure, mechanical properties, and electrical performance were systematically investigated. The results show that an optimal PAN content of 0.25 wt% promotes the formation of high-quality in-situ graphene, which simultaneously strengthens the copper matrix and improves electrical stability. On the mechanical side, the composite showed a yield strength of 408 MPa and a tensile strength of 427 MPa, with increases of 63 % and 42 %, respectively, compared to pure copper. This enhancement is primarily attributed to dislocation strengthening, grain refinement, and load transfer, with graphene reinforcing the composite by restricting dislocation motion, impeding grain growth, and providing the intrinsic high strength of graphene. On the electrical side, the composite maintained a high room-temperature electrical conductivity of 94.2 % IACS while achieving a reduced temperature coefficient of resistance (TCR) of 3.68 × 10 -3 K −1 , which results from the high intrinsic conductivity and negative TCR of graphene. These findings highlight the dual role of PAN-derived graphene in enhancing both the mechanical and electrical properties, offering valuable insights into the development of high-performance graphene/metal composites for industrial applications.